Transmission of punctured null data packets and partial bandwidth feedback

ABSTRACT

A technique for wireless communication of a punctured null data packet with a long training field sequence is disclosed. The long training field (LTF) sequence is generated for the null data packet (NDP) for transmission over a channel having a bandwidth that is an integer multiple of 80 MHz. The LTF sequence is modulated onto a plurality of tones of the channel excluding tones within a punctured subchannel of a plurality of subchannels of the channel. The modulation may be based on a size and location of the punctured subchannel and a symbol duration associated with transmitting the LTF sequence. The NDP is transmitted including the LTF sequence to a second wireless communication device via the channel. A partial bandwidth feedback may be received in response to the LTF in the punctured NDP.

CROSS-REFERENCE TO RELATED APPLICATIONS

This Patent Application is a Continuation of U.S. patent applicationSer. No. 17/356,330 filed on Jun. 23, 2021, and which claims priority toU.S. Provisional Patent Application No. 63/052,453 filed on Jul. 15,2020, and U.S. Provisional Patent Application No. 63/043,775 filed onJun. 24, 2020, the entire content of which is incorporated herein byreference as if fully set forth below in its entirety and for allapplicable purposes.

TECHNICAL FIELD

The present disclosure relates generally to wireless communication, andmore particularly, to transmission of punctured null data packets andpartial bandwidth feedback in wireless communication systems.

DESCRIPTION OF THE RELATED TECHNOLOGY

A wireless local area network (WLAN) may be formed by one or morewireless access points (APs) that provide a shared wirelesscommunication medium for use by multiple client devices also referred toas wireless stations (STAs). The basic building block of a WLANconforming to the Institute of Electrical and Electronics Engineers(IEEE) 802.11 family of standards is a Basic Service Set (BSS), which ismanaged by an AP.

As wireless communications have been evolving toward ever increasingdata rates, the IEEE 802.11 standard has also evolved to provideincreased throughput. Recently, IEEE 802.11be is being developed, whichdefines Extreme High Throughput (EHT) wireless communications usinglarge bandwidth channels (for example, having a bandwidth of 240 MHz,320 MHz, or larger). The total channel bandwidth may be comprised of acombination of subchannels (potentially having different sizes) in oneor more frequency bands (such as the 5 GHz or 6 GHz frequency bands).

IEEE 802.11be proposes to transmit signals using orthogonalfrequency-division multiple access (OFDMA) which is a multi-user versionof the orthogonal frequency-division multiplexing (OFDM) digitalmodulation scheme. OFDM employs multi-carrier modulation where aplurality of carriers (such as, parallel subcarriers), each carrying lowbit rate data, are orthogonal to each other.

In some cases, an AP may communicate with one or more STAs usingmultiple-input multiple-output (MIMO) techniques. For instance, the APmay use beamforming to steer MIMO transmissions to the one or more STAsand reduce signaling interference on the channel for beamformedsignaling targeted to each STA of the one or more STAs. To sendbeamformed MIMO transmissions, the AP may determine channel informationaccording to an explicit sounding procedure that involves a number ofpacket exchanges between the AP and the one or more STAs (for example,target STAs). Such sounding procedure includes the transmission of aLong Training Field (LTF) over one or more subchannels. Channelpuncturing is a technique by which a narrow subchannel of a largerchannel is used for a transmission. However, in some cases, suchexplicit sounding procedure and acquisition of channel information maybe affected by puncturing of subchannels used for such soundingprocedure.

SUMMARY

The following presents a simplified summary of one or more aspects ofthe present disclosure, in order to provide a basic understanding ofsuch aspects. This summary is not an extensive overview of allcontemplated features of the disclosure, and is intended neither toidentify key or critical elements of all aspects of the disclosure norto delineate the scope of any or all aspects of the disclosure. Its solepurpose is to present some concepts of one or more aspects of thedisclosure in a simplified form as a prelude to the more detaileddescription that is presented later.

Some aspects provide a method and device for wireless communication by awireless communication device using a long training field (LTF)sequence. The long training field (LTF) sequence for a null data packet(NDP) may be obtained or generated for transmission over a channelhaving a bandwidth that is an integer multiple of 80 MHz. The LTFsequence may be modulated onto a plurality of tones of the channelexcluding tones within a punctured subchannel of a plurality ofsubchannels of the channel, the modulation being based on a size and alocation of the punctured subchannel and a symbol duration associatedwith transmitting the LTF sequence. A null data packet announcement(NDPA) for transmission over the channel may also be obtained orgenerated. The NDPA including a partial bandwidth information subfieldthat includes an 8-bit subfield for identifying a 242-tone resource unit(RU) start index and an end index, the partial bandwidth informationsubfield identifying an indexed range of feedback tones for channelstate information (CSI). The NDP, including the LTF sequence, may thenbe transmitted to a second wireless communication device via thechannel. The NDPA may also be transmitted to the second wirelesscommunication device via the channel.

In one aspect, the modulation of the LTF sequence onto the plurality oftones is based on an orthogonal frequency division multiple access(OFDMA) data tone plan for an 80 MHz bandwidth channel or an OFDMA datatone plan for each 80 MHz segment of a channel having a bandwidth thatis an integer multiple of 80 MHz. The symbol duration associated withthe LTF sequence may be one of: 12.8 μs plus a guard interval, 6.4 μsplus the guard interval, or 3.2 μs plus the guard interval, and whereinthe guard interval is one of 0.8 μs, 1.6 μs, or 3.2 μs.

In one example, the symbol duration associated with the LTF sequence is12.8 μs plus the guard interval, and wherein the LTF sequence ismodulated onto each tone within a plurality of tone ranges of the OFDMAdata tone plan, and the channel includes an 80 MHz bandwidth portionthat includes the punctured subchannel; the punctured subchannel has a20 MHz bandwidth within the 80 MHz bandwidth portion; the 80 MHzbandwidth portion comprises 1001 tones; and the plurality of tone rangesinclude: tones [−253:−12, 12:253, 259:500] based on the puncturedsubchannel being a first 20 MHz subchannel; tones [−500:−259, 12:253,259:500] based on the punctured subchannel being a second 20 MHzsubchannel adjacent the first 20 MHz subchannel; tones [−500:−259,−253:−12, 259:500] based on the punctured subchannel being a third 20MHz subchannel adjacent the second 20 MHz subchannel; or tones[−500:−259, −253:−12, 12:253] based on the punctured subchannel being afourth 20 MHz subchannel adjacent the third 20 MHz subchannel.

In another example, the symbol duration associated with the LTF sequenceis 12.8 μs plus the guard interval, and wherein the LTF sequence ismodulated onto each tone within a plurality of tone ranges of the OFDMAdata tone plan, the channel includes an 80 MHz bandwidth portion thatincludes the punctured subchannel; the punctured subchannel has a 40 MHzbandwidth within the 80 MHz bandwidth portion; the 80 MHz bandwidthportion comprises 1001 tones; and the plurality of tone ranges include:tones [12:253, 259:500] based on the punctured subchannel being a first40 MHz subchannel; or tones [−500:−259, −253:−12] based on the puncturedsubchannel being a second 40 MHz subchannel adjacent the first 40 MHzsubchannel.

In yet another example, the symbol duration associated with the LTFsequence is 6.4 μs plus the guard interval, and the LTF sequence ismodulated onto every other tone within a plurality of tones ranges ofthe OFDMA data tone plan, and the channel includes an 80 MHz bandwidthportion that includes the punctured subchannel; the punctured subchannelhas a 20 MHz bandwidth within the 80 MHz bandwidth portion; the 80 MHzbandwidth portion comprises 1001 tones; and the plurality of tone rangesinclude: tones [−252:2:−12, 12:2:252, 260:2:500] based on the puncturedsubchannel being a first 20 MHz subchannel; tones [−500:2:−260,12:2:252, 260:2:500] based on the punctured subchannel being a second 20MHz subchannel adjacent the first 20 MHz subchannel; tones [−500:2:−260,−252:2:−12, 260:2:500] based on the punctured subchannel being a third20 MHz subchannel adjacent the second 20 MHz subchannel; or tones[−500:2:−260, −252:2:−12, 12:2:252] based on the punctured subchannelbeing a fourth 20 MHz subchannel adjacent the third 20 MHz subchannel.

According to another aspect, the symbol duration associated with the LTFsequence is 6.4 μs plus the guard interval, and the LTF sequence ismodulated onto every other tone within a plurality of tones ranges ofthe OFDMA data tone plan, and the channel includes an 80 MHz bandwidthportion that includes the punctured subchannel; the punctured subchannelhas a 40 MHz bandwidth within the 80 MHz bandwidth portion; the 80 MHzbandwidth portion comprises 1001 tones; and the plurality of tone rangesinclude: tones [12:2:252, 260:2:500] based on the punctured subchannelbeing a first 40 MHz subchannel; or tones [−500:2:−260, −252:2:−12]based on the punctured subchannel being a second 40 MHz subchanneladjacent the first 40 MHz subchannel.

In yet another aspect, the symbol duration associated with the LTFsequence is 3.2 μs plus a guard interval, and the LTF sequence ismodulated onto every fourth tone within a plurality of tones ranges ofthe OFDMA data tone plan is, and the channel includes an 80 MHzbandwidth portion that includes the punctured subchannel; the puncturedsubchannel has a 20 MHz bandwidth within the 80 MHz bandwidth portion;the 80 MHz bandwidth portion comprises 1001 tones; and the plurality oftone ranges include: tones [−252:4:−12, 12:4:252, 260:4:500] based onthe punctured subchannel being a first 20 MHz subchannel; tones[−500:4:−260, 12:4:252, 260:4:500] based on the punctured subchannelbeing a second 20 MHz subchannel adjacent the first 20 MHz subchannel;tones [−500:4:−260, −252:4:−12, 260:4:500] based on the puncturedsubchannel being a third 20 MHz subchannel adjacent the second 20 MHzsubchannel; or tones [−500:4:−260, −252:4:−12, 12:4:252] based on thepunctured subchannel being a fourth 20 MHz subchannel adjacent the third20 MHz subchannel.

In yet another aspect, the symbol duration associated with the LTFsequence is 3.2 μs plus a guard interval, and the LTF sequence ismodulated onto every fourth tone within a plurality of tones ranges ofthe OFDMA data tone plan is, and the channel includes an 80 MHzbandwidth portion that includes the punctured subchannel; the puncturedsubchannel has a 40 MHz bandwidth within the 80 MHz bandwidth portion;the 80 MHz bandwidth portion comprises 1001 tones; and the plurality oftone ranges include: tones [12:4:252, 260:4:500] based on the puncturedsubchannel being a first 40 MHz subchannel; or tones [−500:4:−260,−252:4:−12] based on the punctured subchannel being a second 40 MHzsubchannel adjacent the first 20 MHz subchannel.

Additionally, according to some aspects, the method and device mayfurther include receiving channel state information (CSI) for thechannel in response to transmitting the NDP with a partial feedbackrequest, the partial feedback request covering less than an 80 MHzbandwidth channel or less than an 80 MHz bandwidth portion of a 160 MHzbandwidth channel or a 320 MHz bandwidth channel, the CSI including onefeedback tone for every n grouped tones of the plurality of tones of thechannel where n=4 or 16, and wherein the CSI is received in an indexedrange of feedback tones within a 242-tone resource unit (RU).

For the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth channel include thestart/end tone indices: (a) indexed tones [−500, −260] that providefeedback for a first 20 MHz subchannel of the 80 MHz bandwidth channel,(b) indexed tones [−252, 12] that provide feedback for a second 20 MHzsubchannel of the 80 MHz bandwidth channel, (c) indexed tones [12, 252]that provide feedback for a third 20 MHz subchannel of the 80 MHzbandwidth channel, and (d) indexed tones [260, 500] that providefeedback for a fourth 20 MHz subchannel of the 80 MHz bandwidth channel.

For the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth portion of the 160 MHzbandwidth channel include the start/end tone indices: [−1012, −772] fora 1st indexed RU, [−764, −524] for a 2nd indexed RU, [−500, −260] for a3rd indexed RU, [−252, −12] for a 4th indexed RU, [12, 252] for a 5thindexed RU, [260, 500] for a 6th indexed RU, [524, 764] for a 7thindexed RU, and [772, 1012] for an 8th indexed RU.

For the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth portion of the 320 MHzbandwidth channel includes the start/end tone indices: [−2036, −1796]for a 1st indexed RU, [−1788, −1548] for a 2nd indexed RU, [−1524,−1284] for a 3rd indexed RU, [−1276, −1036] for a 4th indexed RU,[−1012, −772] for a 5th indexed RU, [−764, −524] for a 6th indexed RU,[−500, −260] for a 7th indexed RU, [−252, −12] for an 8th indexed RU,[12, 252] for an 9th indexed RU, [260, 500] for a 10th indexed RU, [524,764] for a 11th indexed RU, [772, 1012] for a 12th indexed RU, [1036,1276] for a 13th indexed RU, [1284, 1524] for a 14th indexed RU, [1548,1788] for a 15th indexed RU, and [1796, 2036] for a 16th indexed RU.

Additionally, according to some aspects, the method and device mayfurther include receiving channel state information (CSI) for thechannel in response to the transmitting the NDP with a feedback requestfor the entire channel bandwidth, the feedback request covering anentire 80 MHz bandwidth channel or an entire 80 MHz bandwidth portion ofa 160 MHz bandwidth channel or a 320 MHz bandwidth channel, the CSIincluding one feedback tone for every n grouped tones of the pluralityof tones of the channel, where n=4 or 16, and the CSI is received in anindexed range of feedback tones within a 996-tone resource unit (RU). Inone example, a feedback tone set for the entire 80 MHz bandwidth channelwithin the 996-tone RU for n=4 feedback tone spacing is defined as[−500:4:−4, 4:4:500], spanning a region of 1001 tones [−500 to +500],every 4 tones, and with a DC tone region between [−4:4].

In another example, a feedback tone set for the entire 160 MHz bandwidthchannel within the 996-tone RU for n=4 feedback tone spacing isindicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−1012:4:−516, −508:4:−12]that provide feedback for a first 80 MHz subchannel of the 160 MHzbandwidth channel, and (b) indexed tones [12:4:508, 516:4:1012] thatprovide feedback for a second 80 MHz subchannel of the 160 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 320 MHzbandwidth channel within the 996-tone RU for n=4 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−2036:4:−1540,−1532:4:−1036] that provide feedback for a first 80 MHz subchannel ofthe 320 MHz bandwidth channel, (b) indexed tones [−1012:4:−516,−508:4:−12] that provide feedback for a second 80 MHz subchannel of the320 MHz bandwidth channel, (c) indexed tones [12:4:508, 516:4:1012] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, and (d) indexed tones[1036:4:1532, 1540:4:2036] that providefeedback for a second 80 MHz subchannel of the 320 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 80 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include indexed tones [−500:16:−260, −252:16:−12, −4,4, 12:16:252, 260:16:500], spanning a region of 1001 tones [−500:500],every 16 tones, and with a DC tone region between [−4:4].

In yet another example, a feedback tone set for the entire 160 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−1012:16:−772, 764:16:−524,−516, −508, −500:16:−260, −252:16:−12] that provide feedback for a first80 MHz subchannel of the 160 MHz bandwidth channel, and (b) indexedtones [12:16:252, 260:16:500, 508, 516, 524:16:764, 772:16:1012] thatprovide feedback for a second 80 MHz subchannel of the 160 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 320 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−2036:16:−1796,−1788:16:−1548, −1540, −1532, −1524:16:−1284, −1276:16:1036] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, (b) indexed tones [−1012:16:−772, −764:16:−524, −516, −508,−500:16:−260, −252:16:−12] that provide feedback for a second 80 MHzsubchannel of the 320 MHz bandwidth channel, (c) indexed tones[12:16:252, 260:Ng=16:500, 508, 516, 524:16:764, 772:16:1012] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, and (d) indexed tones [1036:16:1276, 1284:16:1524, 1532, 1540,1548:16:1788, 1796:16:2036] that provide feedback for a second 80 MHzsubchannel of the 320 MHz bandwidth channel.

Some other aspects provide a method and device for wirelesscommunication by a wireless communication device for providing channelstate information in the presence of channel puncturing. A null datapacket (NDP) may be received over a channel having a bandwidth that isan integer multiple of 80 MHz, the NDP including a long training field(LTF) that is modulated onto a plurality of tones of the channelexcluding tones within a punctured subchannel of a plurality ofsubchannels of the channel, the modulation being based on a size and alocation of the punctured subchannel and a symbol duration associatedwith transmission of the LTF sequence. A channel state information (CSI)for the channel is generated in response to receiving the NDP with afeedback request for at least a portion of the channel bandwidth, thefeedback request covering at least part of an 80 MHz bandwidth channelor at least part of an 80 MHz bandwidth portion of a 160 MHz bandwidthchannel or a 320 MHz bandwidth channel, the CSI including one feedbacktone for every n grouped tones of the plurality of tones of the channel,where n=4 or 16, and the CSI is modulated in an indexed range offeedback tones within a 242-tone resource unit (RU) or a 996-toneresource unit (RU). A null data packet announcement (NDPA) may also bereceived over the channel, the NDPA including a partial bandwidthinformation subfield that includes an 8-bit subfield for identifying a242-tone resource unit (RU) start index and an end index, the partialbandwidth information subfield identifying an indexed range of feedbacktones for the channel state information (CSI). The CSI is thentransmitted to the first wireless device. According to some aspects, theLTF sequence may be modulated onto the plurality of tones based on anorthogonal frequency division multiple access (OFDMA) data tone plan foran 80 MHz bandwidth channel or an OFDMA data tone plan for each 80 MHzsegment of a channel having a bandwidth that is an integer multiple of80 MHz.

In some aspects, the feedback request is a partial feedback request forless than the 80 MHz bandwidth channel or less than the 80 MHz bandwidthportion of the 160 MHz bandwidth channel or the 320 MHz bandwidthchannel, the CSI including one feedback tone for every n grouped tonesof the plurality of tones of the channel where n=4 or 16, and whereinthe CSI is modulated in an indexed range of feedback tones within the242-tone resource unit (RU).

In one example, for the 242-tone RU of n=4 or n=16 feedback tonespacing, the feedback start/end tone indices for the 80 MHz bandwidthchannel include the start/end tone indices: (a) indexed tones [−500,−260] that provide feedback for a first 20 MHz subchannel of the 80 MHzbandwidth channel, (b) indexed tones [−252, 12] that provide feedbackfor a second 20 MHz subchannel of the 80 MHz bandwidth channel, (c)indexed tones [12, 252] that provide feedback for a third 20 MHzsubchannel of the 80 MHz bandwidth channel, and (d) indexed tones [260,500] that provide feedback for a fourth 20 MHz subchannel of the 80 MHzbandwidth channel.

In yet another example, for the 242-tone RU of n=4 or n=16 feedback tonespacing, the feedback start/end tone indices for the 80 MHz bandwidthportion of the 160 MHz bandwidth channel include the start/end toneindices: [−1012, −772] for a 1st indexed RU, [−764, −524] for a 2ndindexed RU, [−500, −260] for a 3rd indexed RU, [−252, −12] for a 4thindexed RU, [12, 252] for a 5th indexed RU, [260, 500] for a 6th indexedRU, [524, 764] for a 7th indexed RU, and [772, 1012] for an 8th indexedRU.

In yet another example, for the 242-tone RU of n=4 or n=16 feedback tonespacing, the feedback start/end tone indices for the 80 MHz bandwidthportion of the 320 MHz bandwidth channel includes the start/end toneindices: [−2036, −1796] for a 1st indexed RU, [−1788, −1548] for a 2ndindexed RU, [−1524, −1284] for a 3rd indexed RU, [−1276, −1036] for a4th indexed RU, [−1012, −772] for a 5th indexed RU, [−764, −524] for a6th indexed RU, [−500, −260] for a 7th indexed RU, [−252, −12] for an8th indexed RU, [12, 252] for an 9th indexed RU, [260, 500] for a 10thindexed RU, [524, 764] for a 11th indexed RU, [772, 1012] for a 12thindexed RU, [1036, 1276] for a 13th indexed RU, [1284, 1524] for a 14thindexed RU, [1548, 1788] for a 15th indexed RU, and [1796, 2036] for a16th indexed RU.

In one aspect, the feedback request is an entire feedback requestcovering the entire 80 MHz bandwidth channel or the entire 80 MHzbandwidth portion of the 160 MHz bandwidth channel or the 320 MHzbandwidth channel, the CSI including one feedback tone for every ngrouped tones of the plurality of tones of the channel where n=4 or 16,and wherein the CSI is modulated in an indexed range of feedback toneswithin the 996-tone resource unit (RU).

In one example, a feedback tone set for the entire 80 MHz bandwidthchannel within the 996-tone RU for n=4 feedback tone spacing is definedas [−500:4:−4, 4:4:500], spanning a region of 1001 tones [−500 to +500],every 4 tones, and with a DC tone region between [−4:4].

In another example, a feedback tone set for the entire 160 MHz bandwidthchannel within the 996-tone RU for n=4 feedback tone spacing isindicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−1012:4:−516, −508:4:−12]that provide feedback for a first 80 MHz subchannel of the 160 MHzbandwidth channel, and (b) indexed tones [12:4:508, 516:4:1012] thatprovide feedback for a second 80 MHz subchannel of the 160 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 320 MHzbandwidth channel within the 996-tone RU for n=4 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−2036:4:−1540,−1532:4:−1036] that provide feedback for a first 80 MHz subchannel ofthe 320 MHz bandwidth channel, (b) indexed tones [−1012:4:−516,−508:4:−12] that provide feedback for a second 80 MHz subchannel of the320 MHz bandwidth channel, (c) indexed tones [12:4:508, 516:4:1012] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, and (d) indexed tones[1036:4:1532, 1540:4:2036] that providefeedback for a second 80 MHz subchannel of the 320 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 80 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include indexed tones [−500:16:−260, −252:16:−12, −4,4, 12:16:252, 260:16:500], spanning a region of 1001 tones [−500:500],every 16 tones, and with a DC tone region between [−4:4].

In yet another example, a feedback tone set for the entire 160 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−1012:16:−772, 764:16:−524,−516, −508, −500:16:−260, −252:16:−12] that provide feedback for a first80 MHz subchannel of the 160 MHz bandwidth channel, and (b) indexedtones [12:16:252, 260:16:500, 508, 516, 524:16:764, 772:16:1012] thatprovide feedback for a second 80 MHz subchannel of the 160 MHz bandwidthchannel.

In yet another example, a feedback tone set for the entire 320 MHzbandwidth channel within the 996-tone RU for n=16 feedback tone spacingis indicated by feedback start and end tone indices tables for each996-tone RU that include: (a) indexed tones [−2036:16:−1796,−1788:16:−1548, −1540, −1532, −1524:16:−1284, −1276:16:1036] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, (b) indexed tones [−1012:16:−772, −764:16:−524, −516, −508,−500:16:−260, −252:16:−12] that provide feedback for a second 80 MHzsubchannel of the 320 MHz bandwidth channel, (c) indexed tones[12:16:252, 260:Ng=16:500, 508, 516, 524:16:764, 772:16:1012] thatprovide feedback for a first 80 MHz subchannel of the 320 MHz bandwidthchannel, and (d) indexed tones [1036:16:1276, 1284:16:1524, 1532, 1540,1548:16:1788, 1796:16:2036] that provide feedback for a second 80 MHzsubchannel of the 320 MHz bandwidth channel.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of one or more aspects of the subject matter described in thisdisclosure are set forth in the accompanying drawings and thedescription below. However, the accompanying drawings illustrate onlysome typical aspects of this disclosure and are therefore not to beconsidered limiting of its scope. Other features, aspects, andadvantages will become apparent from the description, the drawings andthe claims.

FIG. 1 shows a block diagram of an example wireless communicationnetwork.

FIG. 2A shows an example protocol data unit (PDU) usable for wirelesscommunication between an access point (AP) and one or more wirelessstations (STAs).

FIG. 2B shows an example legacy signal field (L-SIG) in the PDU of FIG.2A.

FIG. 3A shows an example physical layer convergence protocol (PLCP)protocol data unit (PPDU) usable for wireless communication between anAP and one or more STAs.

FIG. 3B shows another example PPDU usable for wireless communicationbetween an AP and one or more STAs.

FIG. 4 shows an example 2N-tone plan.

FIG. 5 illustrates an example of a tone plan for an extreme highthroughput (EHT) 80 MHz bandwidth channel.

FIG. 6 is a table illustrating an orthogonal frequency-division multipleaccess (OFDMA) data tone plan for an 80 MHz bandwidth channel that maybe the basis for a long training field (LTF) tone plan for transmissionof punctured null data packets (NDPs).

FIG. 7 shows a flowchart illustrating an example method for wirelesscommunication including generating and transmitting a long trainingfield sequence for a null data packet according to one aspect.

FIG. 8 illustrates an example of a feedback start/end tone indicestable.

FIG. 9 illustrates another example of a feedback start/end tone indicestable.

FIG. 10 illustrates an example of a feedback start/end tone indicestable.

FIG. 11 illustrates another example of a feedback start/end tone indicestable.

FIG. 12 illustrates yet another example of a feedback start/end toneindices table.

FIG. 13 illustrates yet another option of a feedback start/end toneindices table.

FIG. 14 illustrates an OFDMA feedback start/end tone indices table foran 80 MHz bandwidth channel that may have a 20 MHz granularity.

FIG. 15 shows a flowchart illustrating an example method for wirelesscommunication including generating and transmitting a null data packetannouncement (NDPA) according to some aspects.

FIG. 16 is a block diagram illustrating an example of a wireless deviceadapted to facilitate communications of punctured null data packets andpartial bandwidth feedback using an 80 MHz channel bandwidth.

FIG. 17 illustrates another example of a feedback start/end tone indicestable.

FIG. 18 illustrates yet another option of a feedback start/end toneindices table.

FIG. 19 is a table illustrating specific examples of OFDMA feedbackstart/end tone indices for a partial 80 MHz bandwidth channel for RU242granularity, where the feedback does not cover the entire 80 MHzbandwidth channel.

FIG. 20 is a table illustrating specific examples of OFDMA feedbackstart/end tone indices for an entire 80 MHz bandwidth channel for RU996granularity using n grouped tones Ng=4, where the feedback covers theentire 80 MHz bandwidth channel.

FIG. 21 is a table illustrating specific examples of OFDMA feedbackstart/end tone indices for an entire 80 MHz bandwidth channel for RU996granularity using n grouped tones Ng=16, where the feedback covers theentire 80 MHz bandwidth channel.

FIG. 22 is an example method for wireless communication that providespartial bandwidth feedback in response to receiving a punctured nulldata packet.

Like reference numbers and designations in the various drawings indicatelike elements.

DETAILED DESCRIPTION

The following description is directed to some particular examples forthe purposes of describing innovative aspects of this disclosure.However, a person having ordinary skill in the art will readilyrecognize that the teachings herein can be applied in a multitude ofdifferent ways. Some or all of the described examples may be implementedin any device, system or network that is capable of transmitting andreceiving radio frequency (RF) signals according to one or more of theInstitute of Electrical and Electronics Engineers (IEEE) 802.11standards, the IEEE 802.15 standards, the Bluetooth® standards asdefined by the Bluetooth Special Interest Group (SIG), or the Long TermEvolution (LTE), 3G, 4G or 5G (New Radio (NR)) standards promulgated bythe 3^(rd) Generation Partnership Project (3GPP), among others. Thedescribed implementations can be implemented in any device, system ornetwork that is capable of transmitting and receiving RF signalsaccording to one or more of the following technologies or techniques:code division multiple access (CDMA), time division multiple access(TDMA), frequency division multiple access (FDMA), orthogonal FDMA(OFDMA), single-carrier FDMA (SC-FDMA), single-user (SU) multiple-inputmultiple-output (MIMO) and multi-user (MU)-MIMO. The describedimplementations also can be implemented using other wirelesscommunication protocols or RF signals suitable for use in one or more ofa wireless personal area network (WPAN), a wireless local area network(WLAN), a wireless wide area network (WWAN), or an internet of things(IOT) network.

In some cases, an AP may communicate with one or more STAs usingmultiple-input multiple-output (MIMO) techniques. For instance, the APmay use beamforming to steer MIMO transmissions to the one or more STAsand reduce signaling interference on the channel for beamformedsignaling targeted to each STA of the one or more STAs. To sendbeamformed MIMO transmissions, the AP may determine channel informationaccording to an explicit sounding procedure that involves a number ofpacket exchanges between the AP and the one or more STAs (for example,target STAs). Such sounding procedure includes the transmission of aLong Training Field (LTF) over one or more subchannels. Channelpuncturing is a technique by which a narrow subchannel is used for atransmission to avoid interference. However, in some cases, suchexplicit sounding procedure and acquisition of channel information maybe affected by puncturing of subchannels used for such soundingprocedure.

Various aspects relate generally to transmission of a punctured nulldata packet (NDP) as part of a sounding procedure to obtain channelinformation. Some aspects more specifically relate to using an OFDMAdata tone plan as the basis to modulate a long training field (LTF)sequence in a preamble of the punctured NDP. The tone plan is used tomodulate the LTF sequence onto a plurality of tones of a channelexcluding tones within a punctured subchannel of a plurality ofsubchannels of the channel. In various implementations, the modulationmay be based on a size or location of the punctured subchannel as wellas a symbol duration associated with transmitting the LTF sequence.

An advantage of this approach is that partial channel feedback can beobtained for a channel despite the presence of channel puncturing of asubchannel.

FIG. 1 shows a block diagram of an example wireless communicationnetwork 100. According to some aspects, the wireless communicationnetwork 100 can be an example of a wireless local area network (WLAN)such as a Wi-Fi network (and will hereinafter be referred to as WLAN100). For example, the WLAN 100 can be a network implementing at leastone of the IEEE 802.11 family of wireless communication protocolstandards (such as that defined by the IEEE 802.11-2016 specification oramendments thereof including, but not limited to, 802.11ay, 802.11ax,802.11az, 802.11ba and 802.11be). The WLAN 100 may include numerouswireless communication devices such as an access point (AP) 102 andmultiple stations (STAs) 104. While only one AP 102 is shown, the WLANnetwork 100 also can include multiple APs 102.

Each of the STAs 104 also may be referred to as a mobile station (MS), amobile device, a mobile handset, a wireless handset, an access terminal(AT), a user equipment (UE), a subscriber station (SS), or a subscriberunit, among other examples. The STAs 104 may represent various devicessuch as mobile phones, personal digital assistant (PDAs), other handhelddevices, netbooks, notebook computers, tablet computers, laptops,display devices (for example, TVs, computer monitors, navigationsystems, among others), music or other audio or stereo devices, remotecontrol devices (“remotes”), printers, kitchen or other householdappliances, key fobs (for example, for passive keyless entry and start(PKES) systems), among other examples.

A single AP 102 and an associated set of STAs 104 may be referred to asa basic service set (BSS), which is managed by the respective AP 102.FIG. 1 additionally shows an example coverage area 106 of the AP 102,which may represent a basic service area (BSA) of the WLAN 100. The BSSmay be identified to users by a service set identifier (SSID), as wellas to other devices by a basic service set identifier (BSSID), which maybe a medium access control (MAC) address of the AP 102. The AP 102periodically broadcasts beacon frames (“beacons”) including the BSSID toenable any STAs 104 within wireless range of the AP 102 to “associate”or re-associate with the AP 102 to establish a respective communicationlink 108 (hereinafter also referred to as a “Wi-Fi link”), or tomaintain a communication link 108, with the AP 102. For example, thebeacons can include an identification of a primary channel used by therespective AP 102 as well as a timing synchronization function forestablishing or maintaining timing synchronization with the AP 102. TheAP 102 may provide access to external networks to various STAs 104 inthe WLAN via respective communication links 108.

To establish a communication link 108 with an AP 102, each of the STAs104 is configured to perform passive or active scanning operations(“scans”) on frequency channels in one or more frequency bands (forexample, the 2.4 GHz, 5 GHz, 6 GHz or 60 GHz bands). To perform passivescanning, a STA 104 listens for beacons, which are transmitted byrespective APs 102 at a periodic time interval referred to as the targetbeacon transmission time (TBTT) (measured in time units (TUs) where oneTU may be equal to 1024 microseconds (μs)). To perform active scanning,a STA 104 generates and sequentially transmits probe requests on eachchannel to be scanned and listens for probe responses from APs 102. EachSTA 104 may be configured to identify or select an AP 102 with which toassociate based on the scanning information obtained through the passiveor active scans, and to perform authentication and associationoperations to establish a communication link 108 with the selected AP102. The AP 102 assigns an association identifier (AID) to the STA 104at the culmination of the association operations, which the AP 102 usesto track the STA 104.

As a result of the increasing ubiquity of wireless networks, a STA 104may have the opportunity to select one of many BSSs within range of theSTA or to select among multiple APs 102 that together form an extendedservice set (ESS) including multiple connected BSSs. An extended networkstation associated with the WLAN 100 may be connected to a wired orwireless distribution system that may allow multiple APs 102 to beconnected in such an ESS. As such, a STA 104 can be covered by more thanone AP 102 and can associate with different APs 102 at different timesfor different transmissions. Additionally, after association with an AP102, a STA 104 also may be configured to periodically scan itssurroundings to find a more suitable AP 102 with which to associate. Forexample, a STA 104 that is moving relative to its associated AP 102 mayperform a “roaming” scan to find another AP 102 having more desirablenetwork characteristics such as a greater received signal strengthindicator (RSSI) or a reduced traffic load.

In some cases, STAs 104 may form networks without APs 102 or otherequipment other than the STAs 104 themselves. One example of such anetwork is an ad hoc network (or wireless ad hoc network). Ad hocnetworks may alternatively be referred to as mesh networks orpeer-to-peer (P2P) networks. In some cases, ad hoc networks may beimplemented within a larger wireless network such as the WLAN 100. Insuch implementations, while the STAs 104 may be capable of communicatingwith each other through the AP 102 using communication links 108, STAs104 also can communicate directly with each other via direct wirelesslinks 110. Additionally, two STAs 104 may communicate via a directcommunication link 110 regardless of whether both STAs 104 areassociated with and served by the same AP 102. In such an ad hoc system,one or more of the STAs 104 may assume the role filled by the AP 102 ina BSS. Such a STA 104 may be referred to as a group owner (GO) and maycoordinate transmissions within the ad hoc network. Examples of directwireless links 110 include Wi-Fi Direct connections, connectionsestablished by using a Wi-Fi Tunneled Direct Link Setup (TDLS) link, andother P2P group connections.

The APs 102 and STAs 104 may function and communicate (via therespective communication links 108) according to the IEEE 802.11 familyof wireless communication protocol standards (such as that defined bythe IEEE 802.11-2016 specification or amendments thereof including, butnot limited to, 802.11ay, 802.11ax, 802.11az, 802.11ba and 802.11be).These standards define the WLAN radio and baseband protocols for the PHYand medium access control (MAC) layers. The APs 102 and STAs 104transmit and receive wireless communications (hereinafter also referredto as “Wi-Fi communications”) to and from one another in the form of PHYprotocol data units (PPDUs) (or physical layer convergence protocol(PLCP) PDUs). The APs 102 and STAs 104 in the WLAN 100 may transmitPPDUs over an unlicensed spectrum, which may be a portion of spectrumthat includes frequency bands traditionally used by Wi-Fi technology,such as the 2.4 GHz band, the 5 GHz band, the 60 GHz band, the 3.6 GHzband, and the 900 MHz band. Some implementations of the APs 102 and STAs104 described herein also may communicate in other frequency bands, suchas the 6 GHz band, which may support both licensed and unlicensedcommunications. The APs 102 and STAs 104 also can be configured tocommunicate over other frequency bands such as shared licensed frequencybands, where multiple operators may have a license to operate in thesame or overlapping frequency band or bands.

Each of the frequency bands may include multiple sub-bands or frequencychannels. For example, PPDUs conforming to the IEEE 802.11n, 802.11ac,802.11ax and 802.11be standard amendments may be transmitted over the2.4, 5 GHz or 6 GHz bands, each of which is divided into multiple 20 MHzchannels. As such, these PPDUs are transmitted over a physical channelhaving a minimum bandwidth of 20 MHz, but larger channels can be formedthrough channel bonding. For example, PPDUs may be transmitted overphysical channels having bandwidths of 40 MHz, 80 MHz, 160 or 320 MHz bybonding together multiple 20 MHz channels.

Each PPDU is a composite structure that includes a PHY preamble and apayload in the form of a PHY service data unit (PSDU). The informationprovided in the preamble may be used by a receiving device to decode thesubsequent data in the PSDU. In instances in which PPDUs are transmittedover a bonded channel, the preamble fields may be duplicated andtransmitted in each of the multiple component channels. The PHY preamblemay include both a legacy portion (or “legacy preamble”) and anon-legacy portion (or “non-legacy preamble”). The legacy preamble maybe used for packet detection, automatic gain control and channelestimation, among other uses. The legacy preamble also may generally beused to maintain compatibility with legacy devices. The format of,coding of, and information provided in the non-legacy portion of thepreamble is based on the particular IEEE 802.11 protocol to be used totransmit the payload.

FIG. 2A shows an example protocol data unit (PDU) 200 usable forwireless communication between an AP 102 and one or more STAs 104. Forexample, the PDU 200 can be configured as a PPDU. As shown, the PDU 200includes a PHY preamble 202 and a PHY payload 204. For example, thepreamble 202 may include a legacy portion that itself includes a legacyshort training field (L-STF) 206, which may consist of two BPSK symbols,a legacy long training field (L-LTF) 208, which may consist of two BPSKsymbols, and a legacy signal field (L-SIG) 210, which may consist of twoBPSK symbols. The legacy portion of the preamble 202 may be configuredaccording to the IEEE 802.11 a wireless communication protocol standard.The preamble 202 may also include a non-legacy portion including one ormore non-legacy fields 212, for example, conforming to an IEEE wirelesscommunication protocol such as the IEEE 802.1 lac, 802.11ax, 802.11be orlater wireless communication protocol protocols.

The L-STF 206 generally enables a receiving device to perform coarsetiming and frequency tracking and automatic gain control (AGC). TheL-LTF 208 generally enables a receiving device to perform fine timingand frequency tracking and also to perform an initial estimate of thewireless channel. The L-SIG 210 generally enables a receiving device todetermine a duration of the PDU and to use the determined duration toavoid transmitting on top of the PDU. For example, the L-STF 206, theL-LTF 208 and the L-SIG 210 may be modulated according to a binary phaseshift keying (BPSK) modulation scheme. The payload 204 may be modulatedaccording to a BPSK modulation scheme, a quadrature BPSK (Q-BPSK)modulation scheme, a quadrature amplitude modulation (QAM) modulationscheme, or another appropriate modulation scheme. The payload 204 mayinclude a PSDU including a data field (DATA) 214 that, in turn, maycarry higher layer data, for example, in the form of medium accesscontrol (MAC) protocol data units (MPDUs) or an aggregated MPDU(A-MPDU).

FIG. 2B shows an example L-SIG 210 in the PDU 200 of FIG. 2A. The L-SIG210 includes a data rate field 222, a reserved bit 224, a length field226, a parity bit 228, and a tail field 230. The data rate field 222indicates a data rate (note that the data rate indicated in the datarate field 212 may not be the actual data rate of the data carried inthe payload 204). The length field 226 indicates a length of the packetin units of, for example, symbols or bytes. The parity bit 228 may beused to detect bit errors. The tail field 230 includes tail bits thatmay be used by the receiving device to terminate operation of a decoder(for example, a Viterbi decoder). The receiving device may utilize thedata rate and the length indicated in the data rate field 222 and thelength field 226 to determine a duration of the packet in units of, forexample, microseconds (μs) or other time units.

FIG. 3A shows an example PPDU 300 usable for wireless communicationbetween an AP and one or more STAs. The PPDU 300 may be used for SU,OFDMA or MU-MIMO transmissions. The PPDU 300 may be formatted as a HighEfficiency (HE) WLAN PPDU in accordance with the IEEE 802.11ax amendmentto the IEEE 802.11 wireless communication protocol standard. The PPDU300 includes a PHY preamble including a legacy portion 302 and anon-legacy portion 304. The PPDU 300 may further include a PHY payload306 after the preamble, for example, in the form of a PSDU including adata field 324.

The legacy portion 302 of the preamble includes an L-STF 308, an L-LTF310, and an L-SIG 312. The non-legacy portion 304 includes a repetitionof L-SIG (RL-SIG) 314, a first HE signal field (HE-SIG-A) 316, a HEshort training field (HE-STF) 320, and one or more HE long trainingfields (or symbols) (HE-LTFs) 322. For OFDMA or MU-MIMO communications,the second portion 304 further includes a second HE signal field(HE-SIG-B) 318 encoded separately from HE-SIG-A 316. HE-STF 320 may beused for timing and frequency tracking and AGC, and HE-LTF 322 may beused for more refined channel estimation. Like the L-STF 308, L-LTF 310,and L-SIG 312, the information in RL-SIG 314 and HE-SIG-A 316 may beduplicated and transmitted in each of the component 20 MHz channels ininstances involving the use of a bonded channel. In contrast, thecontent in HE-SIG-B 318 may be unique to each 20 MHz channel and targetspecific STAs 104.

RL-SIG 314 may indicate to HE-compatible STAs 104 that the PPDU 300 isan HE PPDU. An AP 102 may use HE-SIG-A 316 to identify and informmultiple STAs 104 that the AP has scheduled UL or DL resources for them.For example, HE-SIG-A 316 may include a resource allocation subfieldthat indicates resource allocations for the identified STAs 104.HE-SIG-A 316 may be decoded by each HE-compatible STA 104 served by theAP 102. For MU transmissions, HE-SIG-A 316 further includes informationusable by each identified STA 104 to decode an associated HE-SIG-B 318.For example, HE-SIG-A 316 may indicate the frame format, includinglocations and lengths of HE-SIG-Bs 318, available channel bandwidths andmodulation and coding schemes (MCSs), among other examples. HE-SIG-A 316also may include HE WLAN signaling information usable by STAs 104 otherthan the identified STAs 104.

HE-SIG-B 318 may carry STA-specific scheduling information such as, forexample, STA-specific (or “user-specific”) MCS values and STA-specificRU allocation information. In the context of DL MU-OFDMA, suchinformation enables the respective STAs 104 to identify and decodecorresponding resource units (RUs) in the associated data field 324.Each HE-SIG-B 318 includes a common field and at least one STA-specificfield. The common field can indicate RU allocations to multiple STAs 104including RU assignments in the frequency domain, indicate which RUs areallocated for MU-MIMO transmissions and which RUs correspond to MU-OFDMAtransmissions, and the number of users in allocations, among otherexamples. The common field may be encoded with common bits, CRC bits,and tail bits. The user-specific fields are assigned to particular STAs104 and may be used to schedule specific RUs and to indicate thescheduling to other WLAN devices. Each user-specific field may includemultiple user block fields. Each user block field may include two userfields that contain information for two respective STAs to decode theirrespective RU payloads in data field 324.

FIG. 3B shows another example PPDU 350 usable for wireless communicationbetween an AP and one or more STAs. The PPDU 350 may be used for SU,OFDMA or MU-MIMO transmissions. The PPDU 350 may be formatted as anExtreme High Throughput (EHT) WLAN PPDU in accordance with the IEEE802.11be amendment to the IEEE 802.11 wireless communication protocolstandard, or may be formatted as a PPDU conforming to any later(post-EHT) version of a new wireless communication protocol conformingto a future IEEE 802.11 wireless communication protocol standard orother wireless communication standard. The PPDU 350 includes a PHYpreamble including a legacy portion 352 and a non-legacy portion 354.The PPDU 350 may further include a PHY payload 356 after the preamble,for example, in the form of a PSDU including a data field 374.

The legacy portion 352 of the preamble includes an L-STF 358, an L-LTF360, and an L-SIG 362. The non-legacy portion 354 of the preambleincludes an RL-SIG 364 and multiple wireless communication protocolversion-dependent signal fields after RL-SIG 364. For example, thenon-legacy portion 354 may include a universal signal field 366(referred to herein as “U-SIG 366”) and an EHT signal field 368(referred to herein as “EHT-SIG 368”). One or both of U-SIG 366 andEHT-SIG 368 may be structured as, and carry version-dependentinformation for, other wireless communication protocol versions beyondEHT. The non-legacy portion 354 further includes an additional shorttraining field 370 (referred to herein as “EHT-STF 370,” although it maybe structured as, and carry version-dependent information for, otherwireless communication protocol versions beyond EHT) and one or moreadditional long training fields 372 (referred to herein as “EHT-LTFs372,” although they may be structured as, and carry version-dependentinformation for, other wireless communication protocol versions beyondEHT). EHT-STF 370 may be used for timing and frequency tracking and AGC,and EHT-LTF 372 may be used for more refined channel estimation. LikeL-STF 358, L-LTF 360, and L-SIG 362, the information in U-SIG 366 andEHT-SIG 368 may be duplicated and transmitted in each of the component20 MHz channels in instances involving the use of a bonded channel. Insome implementations, EHT-SIG 368 may additionally or alternativelycarry information in one or more non-primary 20 MHz channels that isdifferent than the information carried in the primary 20 MHz channel.

EHT-SIG 368 may include one or more jointly encoded symbols and may beencoded in a different block from the block in which U-SIG 366 isencoded. EHT-SIG 368 may be used by an AP to identify and informmultiple STAs 104 that the AP has scheduled UL or DL resources for them.EHT-SIG 368 may be decoded by each compatible STA 104 served by the AP102. EHT-SIG 368 may generally be used by a receiving device tointerpret bits in the data field 374. For example, EHT-SIG 368 mayinclude RU allocation information, spatial stream configurationinformation, and per-user signaling information such as MCSs, amongother examples. EHT-SIG 368 may further include a cyclic redundancycheck (CRC) (for example, four bits) and a tail (for example, 6 bits)that may be used for binary convolutional code (BCC). In someimplementations, EHT-SIG 368 may include one or more code blocks thateach include a CRC and a tail. In some aspects, each of the code blocksmay be encoded separately.

EHT-SIG 368 may carry STA-specific scheduling information such as, forexample, user-specific MCS values and user-specific RU allocationinformation. EHT-SIG 368 may generally be used by a receiving device tointerpret bits in the data field 374. In the context of DL MU-OFDMA,such information enables the respective STAs 104 to identify and decodecorresponding RUs in the associated data field 374. Each EHT-SIG 368 mayinclude a common field and at least one user-specific field. The commonfield can indicate RU distributions to multiple STAs 104, indicate theRU assignments in the frequency domain, indicate which RUs are allocatedfor MU-MIMO transmissions and which RUs correspond to MU-OFDMAtransmissions, and the number of users in allocations, among otherexamples. The common field may be encoded with common bits, CRC bits,and tail bits. The user-specific fields are assigned to particular STAs104 and may be used to schedule specific RUs and to indicate thescheduling to other WLAN devices. Each user-specific field may includemultiple user block fields. Each user block field may include, forexample, two user fields that contain information for two respectiveSTAs to decode their respective RU payloads.

The presence of RL-SIG 364 and U-SIG 366 may indicate to EHT- or laterversion-compliant STAs 104 that the PPDU 350 is an EHT PPDU or a PPDUconforming to any later (post-EHT) version of a new wirelesscommunication protocol conforming to a future IEEE 802.11 wirelesscommunication protocol standard. For example, U-SIG 366 may be used by areceiving device to interpret bits in one or more of EHT-SIG 368 or thedata field 374.

FIG. 4 shows an example 2N-tone plan 400. In some implementations, thetone plan 400 may correspond to OFDM tones, in the frequency domain,generated using a 2N-point fast Fourier transform (FFT). The tone plan400 includes 2N OFDM tones indexed −N to N−1. The tone plan 400 includestwo sets of edge or guard tones 410, two sets of data/pilot tones 420,and a set of direct current (DC) tones 430. In some implementations, theedge or guard tones 410 and DC tones 430 can be null. In someimplementations, the tone plan 400 may include another suitable numberof pilot tones or may include pilot tones at other suitable tonelocations.

In some aspects, OFDMA tone plans may be provided for transmission usinga 4×symbol duration, as compared to various IEEE 802.11 protocols. Forexample, 4×symbol duration may use a number of symbols which can each be12.8 μs in duration (different from symbols in certain other IEEE 802.11protocols which may be 3.2 μs in duration).

In some aspects, OFDMA tone plans may be provided for transmission usinga 2×symbol duration, as compared to various IEEE 802.11 protocols. Forexample, the 2×symbol duration may use a number of symbols which can beeach 6.4 μs in duration (different from symbols in certain other IEEE802.11 protocols which may be 3.2 μs or 12.8 μs in duration).

In some aspects, the data/pilot tones 420 of a transmission 400 may bedivided among any number of different users. For example, the data/pilottones 420 may be divided among between one and eight users. In order todivide the data/pilot tones 420, an AP 104 or another device may signalto the various devices, indicating which devices may transmit or receiveon which tones (of the data/pilot tones 420) in a particulartransmission. Accordingly, systems and methods for dividing thedata/pilot tones 420 may be desired, and this division may be based upona tone plan.

A tone plan may be chosen based on a number of differentcharacteristics. For example, it may be beneficial to have a simple toneplan, which can be consistent across most or all bandwidths. Forexample, an OFDMA transmission may be transmitted over 20, 40, 80, 160,240, or 320 MHz (or a combination thereof), and it may be desirable touse a tone plan that can be used for any of these bandwidths. Further, atone plan may be simple in that it uses a smaller number of buildingblock sizes. For example, a tone plan may contain a unit which may bereferred to as resource unit (RU). This unit may be used to assign aparticular amount of wireless resources (for example, bandwidth orparticular tones) to a particular user. For example, one user may beassigned bandwidth as a number of RUs, and the data/pilot tones 420 of atransmission may be broken up into a number of RUs.

As previously described, APs and STAs can support multi-user (MU)communications; that is, concurrent transmissions from one device toeach of multiple devices (for example, multiple simultaneous downlink(DL) communications from an AP to corresponding STAs), or concurrenttransmissions from multiple devices to a single device (for example,multiple simultaneous uplink (UL) transmissions from corresponding STAsto an AP). To support the MU transmissions, the APs and STAs may utilizemulti-user multiple-input, multiple-output (MU-MIMO) and multi-userorthogonal frequency division multiple access (MU-OFDMA) techniques.

In MU-OFDMA schemes, the available frequency spectrum of the wirelesschannel may be divided into multiple resource units (RUs) each includingmultiple frequency subcarriers (also referred to as “tones”). DifferentRUs may be allocated or assigned by an AP 102 to different STAs 104 atparticular times. The sizes and distributions of the RUs may be referredto as an RU allocation. In some implementations, RUs may be allocated in2 MHz intervals, and as such, the smallest RU may include 26 tonesconsisting of 24 data tones and 2 pilot tones. Consequently, in a 20 MHzbandwidth channel, up to 9 RUs (such as 2 MHz, 26-tone RUs) may beallocated (because some tones are reserved for other purposes).Similarly, in a 160 MHz bandwidth channel, up to 74 RUs may beallocated. Larger 52 tone, 106 tone, 242 tone, 484 tone and 996 tone RUsmay also be allocated. Adjacent RUs may be separated by a nullsubcarrier (such as a DC subcarrier), for example, to reduceinterference between adjacent RUs, to reduce receiver DC offset, and toavoid transmit center frequency leakage.

A tone plan also may be chosen based on efficiency. For example,transmissions of different bandwidths (for example, 20, 40, 80, 160,240, or 320 MHz, or a combination thereof) may have different numbers oftones. Reducing the number of leftover tones may be beneficial. Further,it may be beneficial if a tone plan is configured to preserve 20, 40,80, 160, 240, or 320 MHz boundaries in some implementations. Forexample, it may be desirable to have a tone plan which allows each 20,40, 80, 160, 240, or 320 MHz portion to be decoded separately from eachother, rather than having allocations which can be on the boundarybetween two different 20, 40, 80, 160, 240, or 320 MHz portions of thebandwidth. For example, it may be beneficial for interference patternsto be aligned with 20, 40, 80, 160, 240, or 320 MHz channels. Further,it may be beneficial to have channel bonding, which also may be known aspreamble puncturing, such that when a 20 MHz transmission and a 40 MHztransmission can be transmitted, to create a 20 MHz “hole” in thetransmission when transmitted over 80, 160, 240, or 320 MHz. This mayallow, for example, a legacy packet to be transmitted in this unusedportion of the bandwidth. This puncturing may apply to any transmission(for example, 20, 40, 80, 160, 240, or 320 MHz transmissions) and maycreate “holes” of at least 20 MHz in the transmission regardless of thechannel or bandwidth being used. Finally, it also may be advantageous touse a tone plan which provides for fixed pilot tone locations in varioustransmissions, such as in different bandwidths.

As data transmission rate demands increase with additional devicesjoining networks or additional data being added for transmission overnetworks, larger channel bandwidths may be introduced, for example fororthogonal frequency-division multiple access (OFDMA) transmissions. Inone example, tone plans for a 320 MHz total channel bandwidth may beintroduced to assist in increasing peak system transmission data ratesand to more efficiently utilize available channels. For example, as newfrequencies are available for use (for example, 6 GHz), these new toneplans for the larger total channel bandwidths may more efficientlyutilize the newly available channels. Moreover, an increased totalbandwidth which may be provided by these new tone plans may allow forbetter rate vs range tradeoff. In this case, the same or a similartransmission rate may be used to provide larger coverage if a largertotal bandwidth is used. Additionally, the larger total channelbandwidths also may increase tone plan efficiency (for example, for aparticular BW, how many tones could be used for data transmission) andalso may increase a number of guard bands. As with any total channelbandwidth being used, different modes may be available depending onchannel availability. For example, current 80 MHz channel bandwidths maybe separated into 20 MHz, 40 MHz, or 80 MHz modes.

FIG. 5 illustrates an example of a tone plan for an extreme highthroughput (EHT) 80 MHz bandwidth channel. The tone plan 500 has 12 leftedge tones 502, 5 DC tones 504, 23 DC tones 506, 5 DC tones 508, and 11right edge tones 510, and a total of 996 usable tones for OFDMA. FIG. 5shows six example transmissions 520, 522, 524, 526, 528, and 530 usingvarious combinations of 26-, 52-, 106-, 242-, 484- and 996 tone blocks.However, allocations within any given transmission can include multipletone blocks of different sizes or having different arrangements. Forinstance, one transmission may include four 20 MHz bandwidth channels,for a total bandwidth of 80 MHz. In second example, another transmissionmay include two 40 MHz bandwidth channels, for a total bandwidth of 80MHz. Yet other transmissions may include multiple subchannels ofdifferent bandwidths, but having a total bandwidth that is an integermultiple of 80 MHz.

The sixth transmission 530 includes a single-user tone plan having 5 DCtones. Accordingly, the SU tone plan can include 996 usable tones.

In some implementations, larger bandwidth (BW) transmissions (forexample, 160 MHz, 240 MHz or 320 MHz) may be generated based on 20, 40,or 80 MHz tone plans. For example, the 40 MHz transmissions and the 80MHz transmissions may be duplicated (for example, four times each) tocreate the 160 MHz and 320 MHz transmissions, respectively.

However, a tone plan is needed for non-data null data packets (NDP)transmissions in which at least one subchannel is punctured. Suchpunctured NDP may include an LTF sequence which is transmitted, forexample, by an AP to obtain channel feedback from one or more STAs. Thetone plan used to modulate the LTF sequence should be capable ofaccounting for the punctured subchannel in a plurality of channels usedto transmit the NDP.

FIG. 6 is a table illustrating an OFDMA data tone plan for an 80 MHzbandwidth channel that may be the basis for a long training field (LTF)tone plan for transmission of punctured NDPs. In this example, a datamay be transmitted according to the OFDMA data tone plan 602 for acomplete 80 MHz bandwidth channel 609, where the data tones span aregion of span 1001 tones [−500:500], a every 4 tones, and with a 7 tonedirect current (DC) gap/region between [−3:3]. For full bandwidthnon-data transmission (such as LTF sequence over NDP), the tone plan 608may span a tone region [−500:−3, 3:500], with every tone used for 4×LTFtones (symbol duration of 12.8 μs plus a guard interval). Similarly, forthe full bandwidth non-data transmission, the tone plan 606 may span atone region [−500:−4, 4:500], with every two tones used for 2×LTF tones(with symbol duration of 6.4 μs plus a guard interval). Likewise, forthe full bandwidth non-data transmission, the tone plan 604 may span atone region [−500:−4, 4:500], with every 4 tones used for 1×LTF tones(with symbol duration of 3.2 μs plus a guard interval).

In the case of a punctured 80 MHz bandwidth channel 610 comprising four(4) 20 MHz subchannels, or two 40 Mhz subchannels, (such that one of thesubchannels is punctured), the LTF sequence within the NDP may betransmitted using a non-data tone plan that depends on which of the four20 MHz subchannels (or two 40 MHz subchannel) is punctured and thesymbol duration of the LTF sequence (1×, 2×, or 4×). Here for 4×LTF, thetable 600 shows that the non-data tone plan is the same as for the OFDMAdata tone plan. However, for 1×LTF and 2×LTF, the table 600 shows thatthe tone plans 604 and 606, respectively, vary depending on the symbolduration for the LFT sequence as well as the relative position of thepunctured subchannel within the plurality of subchannels.

FIG. 7 is an example method for wireless communication includinggenerating and transmitting a long training field sequence for a nulldata packet according to some aspects. At step 702, a long trainingfield (LTF) sequence for a null data packet (NDP) may be generated fortransmission over a channel having a bandwidth that is an integermultiple of 80 MHz.

At step 704, the LTF sequence may be modulated onto a plurality of tonesof the channel excluding tones within a punctured subchannel of aplurality of subchannels of the channel, the modulation being based on asize and location of the punctured subchannel and a symbol durationassociated with transmitting the LTF sequence. For instance, modulationof the LTF sequence onto the plurality of tones may be based on anorthogonal frequency division multiple access (OFDMA) data tone plan foran 80 MHz bandwidth channel or each 80 MHz segment of a wireless channelwhere the total channel bandwidth is an integer multiple of 80 MHz. Thenon-data tones illustrated in FIG. 6 (1×LTF, 2×, LTF, or 4×LTF) may beused for modulation depending on the position of the puncturedsubchannel. In various examples, the punctured subchannel may have abandwidth of 20 MHz or 40 MHz. According to some implementations, thechannel may be a contiguous 80 MHz wireless channel, a contiguous 160MHz wireless channel, a non-contiguous 80 MHz+80 MHz wireless channel, acontiguous 240 MHz wireless channel, a non-contiguous 160 MHz+80 MHzchannel, a contiguous 320 MHz wireless channel, or a non-contiguous 160MHz+160 MHz wireless channel.

In one example, the symbol duration associated with the LTF sequence isone of: 12.8 μs plus a guard interval (4×LTF), 6.4 μs plus the guardinterval (2×LTF), or 3.2 μs plus the guard interval (1×LTF), and theguard interval is one of 0.8 μs, 1.6 us, or 3.2 μs.

According to some aspects, the symbol duration associated with the LTFsequence may be 12.8 μs plus a guard interval (4×LTF). In that case,every tone in the OFDMA data tone plan is used for modulation of the LTFsequence. In one specific example, when the punctured subchannel is 20MHz in bandwidth (within an 80 MHz bandwidth channel or each 80 MHzsegment of a wireless channel where the total channel bandwidth is aninteger multiple of 80 MHz) and the plurality of tones span a toneregion of 1001 tones within the particular 80 MHz channel or segment,the plurality of tones used for modulating the LTF sequence (asillustrated in FIG. 6 ) may be:

(a) every tone in the [−253:−12, 12:253, 259:500] tone region if thepunctured subchannel is a first positioned subchannel;(b) every tone in the [−500:−259, 12:253, 259:500] tone region if thepunctured subchannel is a second positioned subchannel;(c) every tone in the [−500:−259, −253:−12, 259:500] tone region if thepunctured subchannel is a third positioned subchannel; or(d) every tone in the [−500:−259, −253:−12, 12:253] tone region if thepunctured subchannel is a fourth positioned subchannel.

In another specific example, when the punctured subchannel has a 40 MHzbandwidth (within an 80 MHz bandwidth channel or each 80 MHz segment ofa wireless channel where the total channel bandwidth is an integermultiple of 80 MHz) and the plurality of tones span a tone region of1001 tones within the particular 80 MHz channel or segment, theplurality of tones used for modulating the LTF sequence (as illustratedin FIG. 6 ) may be:

(a) every tone in the [12:253, 259:500] tone region if the puncturedsubchannel is a first positioned subchannel; or(b) every tone in the [−500:−259, −253:−12] tone region if the puncturedsubchannel is a second positioned subchannel.

According to another aspect, the symbol duration associated with the LTFsequence may be 6.4 μs plus a guard interval (2×LTF). In that case,every other tone (that is, every even indexed tone) within a subset oftones of the OFDMA data tone plan is used for modulation of the LTFsequence. In one specific example, when the punctured subchannel is 20MHz in bandwidth (within an 80 MHz bandwidth channel or each 80 MHzsegment of a wireless channel where the total channel bandwidth is aninteger multiple of 80 MHz) and the plurality of tones span a toneregion of 1001 tones within the particular 80 MHz channel or segment,the plurality of tones used for modulating the LTF sequence (asillustrated in FIG. 6 ) may be:

(a) every tone in the [−252:2:−12, 12:2:252, 260:2:500] tone region(that is, (that is, every other tone in the tone region [−252:−12,12:252, 260:500]) if the punctured subchannel is a first positionedsubchannel;(b) every tone in the [−500:2:−260, 12:2:252, 260:2:500] tone region(that is, every other tone in the tone region [−500:−260, 12:252,260:500]) if the punctured subchannel is a second positioned subchannel;(c) every tone in the [−500:2:−260, −252:2:−12, 260:2:500] tone region(that is every other tone in the tone region [−500:−260, −252:−12,260:500]) if the punctured subchannel is a third positioned subchannel;or(d) every tone in the [−500:2:−260, −252:2:−12, 12:2:252] tone region(that is every other tone in the tone region [−500:−260, −252:−12,12:252]) if the punctured subchannel is a fourth positioned subchannel.

In another specific example, when the punctured subchannel has a 40 MHzbandwidth (within an 80 MHz bandwidth channel or each 80 MHz segment ofa wireless channel where the total channel bandwidth is an integermultiple of 80 MHz) and the plurality of tones span a tone region of1001 tones within the particular 80 MHz channel or segment, theplurality of tones used for modulating the LTF sequence (as illustratedin FIG. 6 ) may be: (a) every tone in the [12:2:252, 260:2:500] toneregion (that is every even-indexed tone in the tone region [12:252,260:500]) if the punctured subchannel is a first positioned subchannel;or (b) every tone in the [−500:2:−260, −252:2:−12] tone region (that isevery even-indexed tone in the tone region [−500:−260, −252:−12]) if thepunctured subchannel is a second positioned subchannel.

According yet to another aspect, when the symbol duration associatedwith the LTF sequence is 3.2 μs plus a guard interval (1×LTF), everyfourth tone within a subset of tones of the OFDMA tone plan may be usedfor modulation of the LTF sequence. In one specific example, wherein thepunctured subchannel is 20 MHz in bandwidth (within an 80 MHz bandwidthchannel or each 80 MHz segment of a wireless channel where the totalchannel bandwidth is an integer multiple of 80 MHz) and the plurality oftones span a tone region of 1001 tones within the particular 80 MHzchannel or segment, the plurality of tones used for modulating the LTFsequence (as illustrated in FIG. 6 ) may be:

(a) every tone in the [−252:4:−12, 12:4:252, 260:4:500] tone region(that is every fourth tone in the tone region [−252:−12, 12:252,260:500]) if the punctured subchannel is a first positioned subchannel;(b) every tone in the [−500:4:−260, −252:4:−12, 260:4:500] tone region(that is every fourth tone in the tone region [−500:−260, 12:252,260:500]) if the punctured subchannel is a second positioned subchannel;(c) every tone in the [−500:4:−260, −252:4:−12, 260:4:500] tone region(that is every fourth tone in the tone region [−500:−260, −252:−12,260:500]) if the punctured subchannel is a third positioned subchannel;or(d) every tone in [−500:4:−260, −252:4:−12, 12:4:252] tone region (thatis every fourth tone in the tone region [−500:−260, −252:−12, 12:252])if the punctured subchannel is a fourth positioned subchannel.

In another specific example, when the punctured subchannel has a 40 MHzbandwidth (within an 80 MHz bandwidth channel or each 80 MHz segment ofa wireless channel where the total channel bandwidth is an integermultiple of 80 MHz) and the plurality of tones span a tone region of1001 tones within the particular 80 MHz channel or segment, theplurality of tones used for modulating the LTF sequence are: (a) everytone in the [12:4:252, 260:4:500] tone region (that is every fourth tonein the tone region [12:252, 260:500]) if the punctured subchannel is afirst positioned subchannel; or (b) every tone in the [−500:4:−260,−252:4:−12] tone region (that is every fourth tone in the toneregion[−500:−260, −252:−12]) if the punctured subchannel is a secondpositioned subchannel.

At step 706, the NDP including the LTF sequence is transmitted to asecond wireless communication device via the channel.

Once the NDP is transmitted, channel state information (CSI) may bereceived in response to such transmission. However, a feedback tone setis needed to define the grouping of subcarriers in CSI feedback. Notethat while IEEE 802.11ax defines a partial bandwidth CSI start/end toneindices table for RU26 (resource units with 26 tones) and providescoverage for an entire RU996 (996 tones) within an 80 MHz PPDU or each80 MHz segment of a wireless channel where the total channel bandwidthis an integer multiple of 80 MHz, it does not align with RU26 in thesecond and third 20 MHz in the IEEE 802.11be EHT80 tone plan. Also, theindices are different since 802.11ax defines 37 RU26 while IEEE 802.11behas 36 RU26.

According to some aspects, the same IEEE 802.11ax feedback tonesdefinition for Ng=4 for IEEE 802.11be may be reused. The entire feedbacktones set of Ng=4 is [−500:4:−4, 4:4:500], but may be rewritten as[[−244:4:−4, 0, 4:4:244]−256, −8, −4, 4, 8, [−244:4:−4, 0,4:4:244]+256], where [−244:4:−4, 4:4:244] are feedback tones of Ng=4 forHE40.

For partial bandwidth CSI feedback, where only CSI of a subset of RU26are included in the CSI feedback, need to define an Ng=4 CSI feedbackstart/end tone indices table for 802.11be. One option, illustrated inFIG. 8 provides an example of feedback start/end tone indices table forNg=4 for IEEE 802.11be. The table in FIG. 8 may use duplication of theNg=4 table for HE40 in two 40 MHz subbands with tone shifting of −256for the lower 40 MHz and tone shifting of +256 for the upper 40 MHz, andlet adjacent RUs add coverage of 6 feedback tones (±4, ±8, ±256). Forinstance, these 6 feedback tones may not be populated in punctured NDP,and CSI feedback may be extrapolated for these tones in response topunctured NDP. In another instance, these tones are only required to besent in case of full 80 MHz PPDU (or full 80 MHz segment) CSI feedbackwithout puncturing, and not required to be sent otherwise.

In another option, illustrated in an example of feedback start/end toneindices table for Ng=4 for IEEE 802.11be of FIG. 9 , duplication of theNg=4 table of HE40 may be employed where 6 feedback tones (+4, +8, +256)are defined in the feedback tone set but not in the Ng=4 table. Thesetones are only required to be sent in case of full 80 MHz PPDU (or full80 MHz segment) CSI feedback without puncturing, and not required to besent otherwise.

FIG. 17 illustrates yet another option of feedback start/end toneindices table for Ng=4 in IEEE 802.11be. This table is a slightvariation on the approach illustrated in FIG. 9 . In particular, the18^(th) RU26 is empty and the start and end tones for the second andthird 20 MHz have been changed due to shifting of the RUs.

In a general approach, the tones in the feedback tone set should befeedback if they are in the range of an RU start/end tone indices. Notethat puncturing of subchannel in the punctured NDP is RU242 based, andthe tones that are defined in the feedback tone set but in the puncturedRU242 should not be sent. For 6 feedback tones (+4, +8, +256) for Ng=4,if these tones are not populated in NDP (that is, in the punctured NDPcase), they are not required to be sent. These tones are only requiredto be sent in case of full 80 MHz PPDU (or full 80 MHz segment) CSIfeedback without puncturing, and not required to be sent otherwise. Afull 80 MHz PPDU (or full 80 MHz segment) CSI feedback withoutpuncturing is defined as when RUs from the 0^(th) to the 35^(th) arerequested for an 80 MHz non-punctured NDP, or when all RUs within one 80MHz segment (without puncturing in the 80 MHz segment) are requested fora >80 MHz NDP.

Yet another aspect may provide for defining an Ng=16 CSI feedbackstart/end tone indices table for 802.11be. In one option, a feedbacktone set for IEEE 802.11ax may be reused, feedback tones of Ng=16, forIEEE 802.11be. The feedback tones of Ng=16 for HE80 are [−500:16:−4,4:16:500]. According to one option, illustrated in an example of thefeedback start/end tone indices table for Ng=16 for IEEE 802.11be ofFIG. 10 , the Ng=16 feedback tones for HE80 are kept and the table isrevised/modified by making changes for RUs in 2^(nd) & 3^(rd) 20 MHz asshown.

In one approach, in order to provide feedback tones ±4 for Ng=16, ifthese tones are not populated in the punctured NDP, extrapolation may beused to get CSI feedback for these tones. In another approach, if thesetones are not populated in the punctured NDP, feedback tones ±4 may bereplaced by ±12 tones (which are populated tones in 1×/2×/4×LTFs, not inthe Ng=16 feedback tones set, but edge tones of adjacent RUs) in case ofa partial bandwidth CSI feedback with punctured NDP.

In another approach, in order to provide feedback tones ±260 for Ng=16,there may be special treatment depending on the scenario. For instance,if the first 20 MHz subchannel is punctured within an 80 MHz bandwidthchannel (or 80 MHz segment), the feedback tone −260 may be replaced forthe 9^(th) RU26 ([−252:−227] in the second 20 MHz subchannel) by −252(which is a populated tone in 1×/2×/4×LTFs, not in the Ng=16 feedbacktones set, but an edge tone of the 9^(th) RU26). Additionally, if thefourth 20 MHz subchannel is punctured within the 80 MHz bandwidthchannel (or 80 MHz segment), the feedback tone +260 may be replaced forthe 26^(th) RU26 ([227:252] in the third 20 MHz subchannel) by +252(which is a populated tone in 1×/2×/4×LTFs, not in the Ng=16 feedbacktones set, but an edge tone of the 26^(th) RU26).

In another approach, these two feedback tones ±260 may be replaced inthe Ng=16 table as illustrated in FIG. 11 . FIG. 11 illustrates anotherexample of feedback start/end tone indices table for Ng=16 for IEEE802.11be.

FIG. 12 illustrates yet another example of feedback start/end toneindices table for Ng=16 for IEEE 802.11be. In one approach, the feedbacktone set may redefine the feedback tones of Ng=16 for IEEE 802.11be. InIEEE 802.11ax the feedback tones of Ng=16 are [−500:16:−4, 4:16:500]. InIEEE 802.11be, the feedback tones of Ng=16 may be redefined based onduplication of feedback tones set of Ng=16 for HE40 in IEEE 802.11ax, ineach 40 MHz subband, with tone shifting of −256 in the lower 40 MHz andtone shifting of +256 in the upper 40 MHz. The resulting feedback tonesset of Ng=16 for IEEE 802.11be is [[−244:16:−4, 4:16:244]−256, −4, 4,[−244:16:−4, 4:16:244]+256]=[−500:16:−260, −252:16:−12, −4, 4,12:16:252, 260:500], where [−244:16:−4, 4:16:244] are feedback tones ofNg=16 for HE40.

According to an example, the Ng=16 feedback start/end tone indices tablefor feedback tones may be based on duplication of the Ng=16 feedbackstart/end tone indices table of HE40. Two feedback tones (+4) aredefined in the feedback tone set but not in the Ng=16 table. These tonesmay only be required to be sent in case of full 80 MHz PPDU (or full 80MHz segment) CSI feedback, and not required to be sent otherwise.

FIG. 13 illustrates yet another option of feedback start/end toneindices table for Ng=16 in IEEE 802.11be. This table is a slightvariation on the approach illustrated in FIG. 12 . In particular, theNg=16 feedback start/end tone indices table of HE40 is duplicated ineach 40 MHz subband, with tone shifting of −256 in the lower 40 MHz andtone shifting of +256 in the upper 40 MHz, and adjacent RUs providecoverage of two feedback tones (+4). These two feedback tones may not bepopulated in the LTF of the punctured NDP. In the case of feedback tones±4 in response to punctured NDP, one solution may be to extrapolate toget CSI feedback for these tones. Another solution may be to replacethese tones by ±12 (which are populated tones in 1×/2×/4×LTFs, not inthe Ng=16 feedback tones set, but edge tones of adjacent RUs) in case ofpartial BW CSI feedback with punctured NDP.

FIG. 18 illustrates yet another option of feedback start/end toneindices table for Ng=4 in IEEE 802.11be. This table is a slightvariation on the approach illustrated in FIG. 13 . In particular, the18^(th) RU26 is empty and the start and end tones for the second andthird 20 MHz have been changed due to shifting of the RUs.

In general approach, the tones in the feedback tone set are feedback ifthey are in the range of RU start/end tone indices. Puncturing ofsubchannel is RU242 based, and the tones are defined in the feedbacktone set, but in the case of a punctured RU242 these tones should not besent. For instance, for two feedback tones (±4) for Ng=16, if thesetones are not populated in the LTF of the NDP (that is, in the puncturedNDP case), they are not required to be sent. These tones are onlyrequired to be sent in case of full 80 MHz PPDU (or full 80 MHz segment)CSI feedback without puncturing, and not required to be sent otherwise.A full 80 MHz PPDU (or full 80 MHz segment) CSI feedback withoutpuncturing is defined as when RUs from the 0^(th) to the 35^(th) arerequested for an 80 MHz non-punctured NDP, or when all RUs within one 80MHz segment (without puncturing in the 80 MHz segment) are requested fora >80 MHz NDP.

To accommodate PPDUs greater than 80 MHz in bandwidth (such as,160/80+80/240/160+80/320/160+160 MHz PPDUs), the tone plan may beduplicates of the EHT80 tone plan. The LTF tones in a punctured NDP andfeedback start/end tone indices for Ng=4 and Ng=16 could be generalizedin the following way. The 80 MHz segments in 80+80/160+80 MHz use sametone indices. The 160 MHz PPDU and 160 MHz segments in 160+80/160+160MHz use [tone indices−512, tone indices+512]. The 320 MHz PPDU uses[tone indices−1536, tone indices−512, tone indices+512, toneindices+1536]. Lastly, the 240 MHz PPDU uses either [tone indices−1536,tone indices −512, tone indices+512] or [tone indices−512, toneindices+512, tone indices+1536].

The RU26 indices in the start/end tone indices table for the 80 MHz PPDUis from 0^(th) to 35^(th). And they could be generalized in thefollowing way: (i) the RU26 indices for the 160/80+80 MHz PPDUs are from0^(th) to 71^(st), (ii) the RU26 indices for the 240/160+80 MHz PPDUsare from 0^(th) to 107^(th), and (iii) the RU26 indices for the320/160+160 MHz PPDUs are from 0^(th) to 143^(rd).

Referring again to FIG. 7 , at step 708, channel state information (CSI)for the channel may be received in response to the transmitted NDP, theCSI including one feedback tone for every n grouped tones of theplurality of tones of the channel, where n=4 or 16, and where:

(a) feedback tones at +/−4, +/−8, and +/−256 for n=4 are only sent ifthese tones are populated LTF tones and feedback tones span the entireregion of 80 MHz; or(b) feedback tones at +/−4, +/−8, and +/−256 for n=4, and feedback tonesat +/−4 for n=16, if these tones are not populated LTF tones, areextrapolated from at least one adjacent populated LTF tone of theplurality of tones of the channel; or(c) feedback tones at +/−4 for n=16, if these tones are not populatedLTF tones, are replaced by tones at +/−12 for n=16 in feedback.

In one example, a feedback tone set for n=4 is defined as [−500:4:−4,4:4:500], spanning a region of 1001 tones [−500:500], every 4 tones, andwith a DC gap between [−2:2].

In one example, a feedback tone set for n=4 may be defined as[−500:4:−4, 4:4:500], spanning a region of 1001 tones [−500:500], every4 tones, and with a DC gap between [−2:2]. The feedback tones at +/−4,+/−8, and +/−256 are not sent when corresponding tones in the NDP arenot populated.

In another example, a feedback tone set for n=16 is defined as[−500:16:−4, 4:16:500], spanning a region of 1001 tones [−500:500],every 16 tones, and with a DC tone region between [−2:2].

In yet another example, a feedback tone set for n=16 is defined as[−500:16:−260, −252:16:−12, −4, 4, 12:16:252, 260:500], spanning aregion of 1001 tones [−500:−260, −252:−12, −4, 4, 12:252, 260:500],every 16 tones, and with a DC tone region between [−2:].

In some implementations, the feedback tones at +/−4 are not sent whencorresponding tones in the NDP are not populated.

A null data packet announcement (NDPA) is typically sent by a basestation to identify intended recipients and a format of the forthcomingsounding frame, and is followed by a sounding NDP. In IEEE 802.11ax, theNDPA has a 14-bit partial bandwidth info subfield, which includes a7-bit RU Start Index subfield and a 7-bit RU End Index subfield.

IEEE 802.11be may use partial bandwidth CSI feedback with same RU26granularity as in 802.11ax. Alternatively, 802.11be may restrict partialbandwidth CSI feedback with a 20 MHz granularity (RU242).

In some aspects for IEEE 802.11be, RU26 granularity may be used forpartial bandwidth channel state information (CSI) feedback.Consequently, there are total 36×4=144 RU26 in a 320 MHz PPDU, 8 bitsare needed to represent the RU start index and 8 bits are needed for theRU end index (a total 16 bits for the partial bandwidth info subfield inNDPA).

In another aspect for IEEE 802.11be, RU242 granularity may be used forpartial bandwidth CSI feedback. In such case, there are total 4×4=16RU242 in a 320 MHz PPDU, 4 bits are needed for the RU start index and 4bits for the RU end index (a total 8 bits for the partial bandwidth infosubfield in NDPA).

In order to reduce the size of the info subfield in NDPA, if the partialbandwidth CSI feedback request has 20 MHz granularity, some aspectspropose to use RU242 start/end indices in the 802.11be NDPA.

FIG. 14 illustrates an OFDMA feedback start/end tone indices table foran 80 MHz bandwidth channel (or an 80 MHz segment of a larger bandwidthchannel that is a multiple of 80 MHz) that may have a 20 MHzgranularity. In this example, the table defines the feedback start/endtone indices 1400 for channel state information (CSI) where the CSIincludes one feedback tone for every n grouped tones of the plurality oftones of the channel, where n=4 or 16.

A general approach may be designed to accommodate channels havingvarious bandwidth portions. Channel state information (CSI) for thechannel may be received in response to the transmitted NDP, the CSIincluding one feedback tone for every n grouped tones of the pluralityof tones of the channel, where n=4 or 16. The CSI may be indicated byfeedback start and end tone indices tables for each 26-tone RU that: (a)duplicates a High Efficiency (HE) feedback start/end tone indices tablefor 40 MHz bandwidth channels to form an entire table of an 80 MHzphysical layer convergence protocol (PLCP) protocol data unit (PPDU),(b) the feedback start/end tone indices of RU26 in the first 40 MHz isbased on start/end tone indices for the HE feedback start/end toneindices table for 40 MHz that are shifted by −256 tones, and (c) thefeedback start/end tone indices of RU26 in the second 40 MHz is based onstart/end tone indices for the HE feedback start/end tone indices tablefor 40 MHz that are shifted by +256 tones. For the channel havingbandwidth portions in 80 MHz segments within 80+80 MHz or 160+80 MHzPPDUs, this same feedback start/end tone indices table is used. For thechannel having bandwidth portions in 160 MHz segments within 160 MHz,160+80 MHz, or 160+160 MHz PPDUs, the feedback start/end tone indicestable is a duplication of two tables for 80 MHz, with tone indicesshifted by −512 tones for the RU26 in a lower 80 MHz and +512 tones forthe RU26 in an upper 80 MHz, respectively. For the channel havingbandwidth portions in a 320 MHz PPDU, the feedback start/end toneindices table is a duplication of four tables for 80 MHz, with toneindices shifted by −1536 tones for an RU26 in a first 80 MHz, −512 tonesfor an RU26 in a second 80 MHz, +512 tones for an RU26 in a third 80MHz, and +1536 tones for an RU26 in a fourth 80 MHz, respectively. Forthe channel having bandwidth portions in 240 MHz segments, the feedbackstart/end tone indices table is a duplication of three tables for 80MHz, with tone indices shifted by: (a) −1536 tones for an RU26 in afirst 80 MHz, −512 tones for an RU26 in a second 80 MHz, and +512 tonesfor an RU26 in a third 80 MHz, respectively, or (b) −512 tones for anRU26 in a first 80 MHz, +512 tones for an RU26 in a second 80 MHz, and+1536 tones for an RU26 in a third 80 MHz, respectively.

FIG. 19 illustrates specific examples of OFDMA feedback start/end toneindices table for a partial 80 MHz bandwidth channel (or an 80 MHzsegment of a larger bandwidth channel that is a multiple of 80 MHz) forRU242 granularity, where the feedback does not cover the entire 80 MHzbandwidth channel or segment. In this table, the start/end indices for ngrouped tones Ng=4 or Ng=16 of FIG. 14 are illustrated in more detail.Note that for 160 MHz bandwidth channel and 320 MHz bandwidth channel,the feedback tone set of 80 MHz bandwidth channel is duplicated in each80 MHz segment. Within the entire 80 MHz bandwidth channel or each 80MHz segment of a 160 MHz or 320 MHz bandwidth channel, if certain RU242is not within the range of a feedback request, only the feedback tonesof the remaining RU242 in that 80 MHz bandwidth channel or segment thatare within the range of feedback request are sent.

Specifically, for feedback of a portion or segment of an 80 MHzbandwidth channel, RU242 index 1 is [−500:Ng:−260], index 2 is[−252:Ng:−12], index 3 is [12:Ng:252], and index 4 is [260:Ng:500].

Similarly, for feedback of a portion or segment of an 160 MHz bandwidthchannel, RU242 index 1 is [−1012:Ng:−772], index 2 is [−764:Ng:−524],index 3 is [−500:Ng:−260], index 4 is [−252:Ng:−12], index 5 is[12:Ng:252], index 6 is [260:Ng:500], index 7 is [524:Ng:764], and index8 is [772:Ng:1012].

Likewise, for feedback of a portion or segment of an 320 MHz bandwidthchannel, RU242 index 1 is [−2036:Ng:−1796], index 2 is [−1788:Ng:−1548],index 3 is [−1524:Ng:−1284], index 4 is [−1276:Ng:−1036], index 5 is[−1012:Ng:−722], index 6 is [−764:Ng:−524], index 7 is [−500:Ng:−260],index 8 is [−252:Ng:−12], index 9 is [12:Ng:252], index 10 is[260:Ng:500], index 11 is [524:Ng:764], index 12 is [772:Ng:1012], index13 is [1036:Ng:1276], index 14 is [1284:Ng:1524], index 15 is[1548:Ng:1788], and index 16 is [1796:Ng:2036].

FIG. 20 is a table illustrating specific examples of OFDMA feedbackstart/end tone indices for an entire 80 MHz bandwidth channel for RU996granularity using n grouped tones Ng=4, where the feedback covers theentire 80 MHz bandwidth channel. Note that for 160 MHz bandwidth channeland 320 MHz bandwidth channel, the feedback tone set of 80 MHz bandwidthchannel is duplicated in each 80 MHz segment. If the entire 80 MHzbandwidth channel or each 80 MHz segment of a 160 MHz or 320 MHzbandwidth channel is within the range of feedback request, the feedbacktones of the RU996 corresponding to that 80 MHz are sent.

Specifically, for feedback of an entire 80 MHz bandwidth channel, RU996index 1 is [−500:4:−4, 4:4:500].

Similarly, for feedback of an entire 80 MHz segment within a 160 MHzbandwidth channel, RU996 index 1 is [−1012:4:−516, −508:4:−12], andindex 2 is [12:4:508, 516:4:1012].

Likewise, for feedback of an entire 80 MHz segment within a 320 MHzbandwidth channel, RU996 index 1 is [−2036:4:−1540, −1532:4:−1036],index 2 is [−1012:4:−516, −508:4:−12], index 3 is [12:4:508,516:4:1012], and index 4 is [1036:4:1532, 1540:4:2036].

FIG. 21 is a table illustrating specific examples of OFDMA feedbackstart/end tone indices for an entire 80 MHz bandwidth channel for RU996granularity using n grouped tones Ng=16, where the feedback covers theentire 80 MHz bandwidth channel.

Note that for 160 MHz bandwidth channel and 320 MHz bandwidth channel,the feedback tone set of 80 MHz bandwidth channel is duplicated in each80 MHz segment. If the entire 80 MHz bandwidth channel or each 80 MHzsegment of a 160 MHz or 320 MHz bandwidth channel is within the range offeedback request, the feedback tones of the RU996 corresponding to that80 MHz are sent.

Specifically, for feedback of an entire 80 MHz bandwidth channel, RU996index 1 is [−500:16:−260, −252:16:−12, −4, 4, 12:16:252, 260:16:500].

Similarly, for feedback of an entire 80 MHz segment within a 160 MHzbandwidth channel, RU996 index 1 is [−1012:16:−772, 764:16:−524, −516,−508, −500:16:−260, −252:16:−12], and index 2 is [12:16:252, 260:16:500,508, 516, 524:16:764, 772:16:1012].

Likewise, for feedback of an entire 80 MHz segment within a 320 MHzbandwidth channel, RU996 index 1 is [−2036:16:−1796, −1788:16:−1548,−1540, −1532, −1524:16:−1284, −1276:16:1036], index 2 is [−1012:16:−772,−764:16:−524, −516, −508, −500:16:−260, −252:16:−12], index 3 is[12:16:252, 260:16:500, 508, 516, 524:16:764, 772:16:1012], and index 4is [1036:16:1276, 1284:16:1524, 1532, 1540, 1548:16:1788, 1796:16:2036].

FIG. 15 is an example method 1500 for wireless communication includinggenerating and transmitting a null data packet announcement (NDPA)according to some aspects. At step 1502, the null data packetannouncement (NDPA) may be obtained generated for transmission over thechannel, the NDPA including a partial bandwidth information subfieldthat includes one of either: (a) a 16-bit subfield for identifying a26-tone resource unit (RU) start index and an end index, or (b) an 8-bitsubfield for identifying a 242-tone resource unit (RU) start index andan end index, the partial bandwidth information subfield identifying anindexed range of feedback tones for channel state information (CSI).

At step 1504, a long training field (LTF) sequence may be generated fora null data packet (NDP) for transmission over a channel having abandwidth that is an integer multiple of 80 MHz.

At step 1506, the LTF sequence may be modulated onto a plurality oftones of the channel excluding tones within a punctured subchannel of aplurality of subchannels of the channel, the modulation being based on asize and a location of the punctured subchannel and a symbol durationassociated with transmitting the LTF sequence.

At step 1508, the NDPA may be transmitted to a second wirelesscommunication device via the channel.

At step 1510, the NDP, including the LTF sequence, may also betransmitted to the second wireless communication device via the channel.

In one example, 26-tone RUs may be used for CSI feedback granularity,and the 16-bit subfield includes an 8-bit start index and an 8-bit endindex.

At step 1512, channel state information (CSI) may be received for thechannel in response to the transmitted NDP, the CSI including onefeedback tone for every n grouped tones of the plurality of tones of thechannel, where n=4 or 16.

In one implementation, where n=4, the CSI is indicated by feedback startand end tone indices tables for each 26-tone RU that duplicates a HighEfficiency (HE) feedback start/end tone indices table for 40 MHzbandwidth channels to form an entire table of an 80 MHz physical layerconvergence protocol (PLCP) protocol data unit (PPDU). The feedbackstart/end tone indices of RU26 in a first 40 MHz is based on start/endtone indices for the HE feedback start/end tone indices table for 40 MHzthat are shifted by −256 tones. The feedback start/end tone indices ofRU26 in a second 40 MHz is based on start/end tone indices for the HEfeedback start/end tone indices table for 40 MHz that are shifted by+256 tones. The feedback start and end tone indices tables for each26-tone RU may further provide coverage of extra feedback tones by usingadjacent RUs, where the extra feedback tones are (±4, ±8, +256).

In the example illustrated in FIG. 8 for n=4, the feedback start/endtone indices for 80 MHz bandwidth channels includes the start/end toneindices:

[−500, −472] for an 0th indexed RU,

[−476, −448] for an 1th indexed RU,

[−448, −420] for an 2th indexed RU,

[−420, −392] for an 3th indexed RU,

[−392, −364] for an 4th indexed RU,

[−368, −340] for an 5th indexed RU,

[−340, −312] for an 6th indexed RU,

[−312, −284] for an 7th indexed RU,

[−288, −256] for an 8th indexed RU,

[−256, −224] for an 9th indexed RU,

[−228, −200] for an 10th indexed RU,

[−200, −172] for an 11th indexed RU,

[−172, −144] for an 12th indexed RU,

[−148, −120] for an 13th indexed RU,

[−120, −92] for an 14th indexed RU,

[−92, −64] for an 15th indexed RU,

[−64, −36] for an 16th indexed RU,

[−40, −4] for an 17th indexed RU,

[4, 40] for an 18th indexed RU,

[36, 64] for an 19th indexed RU,

[64, 92] for an 20th indexed RU,

[92, 120] for an 21th indexed RU,

[120, 148] for an 22th indexed RU,

[144, 172] for an 23th indexed RU,

[172, 200] for an 24th indexed RU,

[200, 228] for an 25th indexed RU,

[224, 256] for an 26th indexed RU,

[256, 288] for an 27th indexed RU,

[284, 312] for an 28th indexed RU,

[312, 340] for an 29th indexed RU,

[340, 368] for an 30th indexed RU,

[364, 392] for an 31th indexed RU,

[392, 420] for an 32th indexed RU,

[420, 448] for an 33th indexed RU,

[448, 476] for an 34th indexed RU, and

[472, 500] for an 35th indexed RU.

In the example illustrated in FIG. 9 for n=4, the feedback start/endtone indices for 80 MHz bandwidth channels includes the start/end toneindices:

[−500, −472] for an 0th indexed RU,

[−476, −448] for an 1th indexed RU,

[−448, −420] for an 2th indexed RU,

[−420, −392] for an 3th indexed RU,

[−392, −364] for an 4th indexed RU,

[−368, −340] for an 5th indexed RU,

[−340, −312] for an 6th indexed RU,

[−312, −284] for an 7th indexed RU,

[−288, −256] for an 8th indexed RU,

[−252, −224] for an 9th indexed RU,

[−228, −200] for an 10th indexed RU,

[−200, −172] for an 11th indexed RU,

[−172, −144] for an 12th indexed RU,

[−148, −120] for an 13th indexed RU,

[−120, −92] for an 14th indexed RU,

[−92, −64] for an 15th indexed RU,

[−64, −36] for an 16th indexed RU,

[−40, −12] for an 17th indexed RU,

[12, 40] for an 18th indexed RU,

[36, 64] for an 19th indexed RU,

[64, 92] for an 20th indexed RU,

[92, 120] for an 21th indexed RU,

[120, 148] for an 22th indexed RU,

[144, 172] for an 23th indexed RU,

[172, 200] for an 24th indexed RU,

[200, 228] for an 25th indexed RU,

[224, 252] for an 26th indexed RU,

[260, 288] for an 27th indexed RU,

[284, 312] for an 28th indexed RU,

[312, 340] for an 29th indexed RU,

[340, 368] for an 30th indexed RU,

[364, 392] for an 31th indexed RU,

[392, 420] for an 32th indexed RU,

[420, 448] for an 33th indexed RU,

[448, 476] for an 34th indexed RU, and

[472, 500] for an 35th indexed RU.

In another implementation, where n=16, the CSI may be indicated byfeedback start and end tone indices tables for each 26-tone RU that aredefined based on a High Efficiency (HE) feedback start/end tone indicestable for 80 MHz bandwidth channels.

In a first example illustrated in FIG. 10 for n=16, the feedbackstart/end tone indices for 80 MHz bandwidth channels includes thestart/end tone indices:

[−500, −468] for an 0th indexed RU,

[−484, −436] for an 1th indexed RU,

[−452, −420] for an 2th indexed RU,

[−420, −388] for an 3th indexed RU,

[−404, −356] for an 4th indexed RU,

[−372, −340] for an 5th indexed RU,

[−340, −308] for an 6th indexed RU,

[−324, −276] for an 7th indexed RU,

[−292, −260] for an 8th indexed RU,

[−260, −212] for an 9th indexed RU,

[−228, −196] for an 10th indexed RU,

[−212, −164] for an 11th indexed RU,

[−180, −132] for an 12th indexed RU,

[−148, −116] for an 13th indexed RU,

[−132, −84] for an 14th indexed RU,

[−100, −52] for an 15th indexed RU,

[−68, −36] for an 16th indexed RU,

[−52, −4] for an 17th indexed RU,

[4, 52] for an 18th indexed RU,

[36, 68] for an 19th indexed RU,

[52, 100] for an 20th indexed RU,

[84, 132] for an 21th indexed RU,

[116, 148] for an 22th indexed RU,

[132, 180] for an 23th indexed RU,

[164, 212] for an 24th indexed RU,

[196, 228] for an 25th indexed RU,

[212, 260] for an 26th indexed RU,

[260, 292] for an 27th indexed RU,

[276, 324] for an 28th indexed RU,

[308, 340] for an 29th indexed RU,

[340, 372] for an 30th indexed RU,

[356, 404] for an 31th indexed RU,

[388, 420] for an 32th indexed RU,

[420, 452] for an 33th indexed RU,

[436, 484] for an 34th indexed RU, and

[468, 500] for an 35th indexed RU.

In a second example illustrated in FIG. 11 for n=16, the feedbackstart/end tone indices for 80 MHz bandwidth channels includes thestart/end tone indices:

[−500, −468] for an 0th indexed RU,

[−484, −436] for an 1th indexed RU,

[−452, −420] for an 2th indexed RU,

[−420, −388] for an 3th indexed RU,

[−404, −356] for an 4th indexed RU,

[−372, −340] for an 5th indexed RU,

[−340, −308] for an 6th indexed RU,

[−324, −276] for an 7th indexed RU,

[−292, −260] for an 8th indexed RU,

[−252, −212] for an 9th indexed RU,

[−228, −196] for an 10th indexed RU,

[−212, −164] for an 11th indexed RU,

[−180, −132] for an 12th indexed RU,

[−148, −116] for an 13th indexed RU,

[−132, −84] for an 14th indexed RU,

[−100, −52] for an 15th indexed RU,

[−68, −36] for an 16th indexed RU,

[−52, −4] for an 17th indexed RU,

[4, 52] for an 18th indexed RU,

[36, 68] for an 19th indexed RU,

[52, 100] for an 20th indexed RU,

[84, 132] for an 21th indexed RU,

[116, 148] for an 22th indexed RU,

[132, 180] for an 23th indexed RU,

[164, 212] for an 24th indexed RU,

[196, 228] for an 25th indexed RU,

[212, 252] for an 26th indexed RU,

[260, 292] for an 27th indexed RU,

[276, 324] for an 28th indexed RU,

[308, 340] for an 29th indexed RU,

[340, 372] for an 30th indexed RU,

[356, 404] for an 31th indexed RU,

[388, 420] for an 32th indexed RU,

[420, 452] for an 33th indexed RU,

[436, 484] for an 34th indexed RU, and

[468, 500] for an 35th indexed RU.

In a third example illustrated in FIG. 12 for n=16, the feedbackstart/end tone indices for 80 MHz bandwidth channels includes thestart/end tone indices:

[−500, −468] for an 0^(th) indexed RU,

[−484, −436] for an 1^(th) indexed RU,

[−452, −420] for an 2^(th) indexed RU,

[−420, −388] for an 3^(th) indexed RU,

[−404, −356] for an 4^(th) indexed RU,

[−372, −340] for an 5^(th) indexed RU,

[−340, −308] for an 6^(th) indexed RU,

[−324, −276] for an 7^(th) indexed RU,

[−292, −260] for an 8^(th) indexed RU,

[−252, −220] for an 9^(th) indexed RU,

[−236, −188] for an 10^(th) indexed RU,

[−204, −172] for an 11^(th) indexed RU,

[−172, −140] for an 12^(th) indexed RU,

[−156, −108] for an 13^(th) indexed RU,

[−124, −92] for an 14^(th) indexed RU,

[−92, −60] for an 15^(th) indexed RU,

[−76, −28] for an 16^(th) indexed RU,

[−44, −12] for an 17^(th) indexed RU,

[12, 44] for an 18^(th) indexed RU,

[28, 76] for an 19^(th) indexed RU,

[60, 92] for an 20^(th) indexed RU,

[92, 124] for an 21^(th) indexed RU,

[108, 156] for an 22^(th) indexed RU,

[140, 172] for an 23^(th) indexed RU,

[172, 204] for an 24^(th) indexed RU,

[188, 236] for an 25^(th) indexed RU,

[220, 252] for an 26^(th) indexed RU,

[260, 292] for an 27^(th) indexed RU,

[276, 324] for an 28^(th) indexed RU,

[308, 340] for an 29^(th) indexed RU,

[340, 372] for an 30^(th) indexed RU,

[356, 404] for an 31^(th) indexed RU,

[388, 420] for an 32^(th) indexed RU,

[420, 452] for an 33^(th) indexed RU,

[436, 484] for an 34^(th) indexed RU, and

[468, 500] for an 35^(th) indexed RU.

In a fourth example illustrated in FIG. 13 for n=16, the feedbackstart/end tone indices for 80 MHz bandwidth channels includes thestart/end tone indices:

[−500, −468] for an 0^(th) indexed RU,

[−484, −436] for an 1^(th) indexed RU,

[−452, −420] for an 2^(th) indexed RU,

[−420, −388] for an 3^(th) indexed RU,

[−404, −356] for an 4^(th) indexed RU,

[−372, −340] for an 5^(th) indexed RU,

[−340, −308] for an 6^(th) indexed RU,

[−324, −276] for an 7^(th) indexed RU,

[−292, −260] for an 8^(th) indexed RU,

[−252, −220] for an 9^(th) indexed RU,

[−236, −188] for an 10^(th) indexed RU,

[−204, −172] for an 11^(th) indexed RU,

[−172, −140] for an 12^(th) indexed RU,

[−156, −108] for an 13^(th) indexed RU,

[−124, −92] for an 14^(th) indexed RU,

[−92, −60] for an 15^(th) indexed RU,

[−76, −28] for an 16^(th) indexed RU,

[−44, −4] for an 17^(th) indexed RU,

[4, 44] for an 18^(th) indexed RU,

[28, 76] for an 19^(th) indexed RU,

[60, 92] for an 20^(th) indexed RU,

[92, 124] for an 21^(th) indexed RU,

[108, 156] for an 22^(th) indexed RU,

[140, 172] for an 23^(th) indexed RU,

[172, 204] for an 24^(th) indexed RU,

[188, 236] for an 25^(th) indexed RU,

[220, 252] for an 26^(th) indexed RU,

[260, 292] for an 27^(th) indexed RU,

[276, 324] for an 28^(th) indexed RU,

[308, 340] for an 29^(th) indexed RU,

[340, 372] for an 30^(th) indexed RU,

[356, 404] for an 31^(th) indexed RU,

[388, 420] for an 32^(th) indexed RU,

[420, 452] for an 33^(th) indexed RU,

[436, 484] for an 34^(th) indexed RU, and

[468, 500] for an 35^(th) indexed RU.

In some implementations, 242-tone RUs may be used for CSI feedbackgranularity, and the 8-bit subfield includes a 4-bit start index and a4-bit end index. Channel state information (CSI) for the channel may bereceived in response to the transmitted NDP, the CSI including onefeedback tone for every n grouped tones of the plurality of tones of thechannel, where n=4 or 16.

In one example illustrated in FIG. 14 , where n=4, the CSI may beindicated by feedback start and end tone indices tables for each242-tone RU that includes:

(a) indexed tones [−500:4:−260] that provide feedback for a first 20 MHzsubchannel,

(b) indexed tones [−252:4:−12] that provide feedback for a second 20 MHzsubchannel,

(c) indexed tones [12:4:252] that provide feedback for a third 20 MHzsubchannel, and

(d) indexed tones [260:4:500] that provide feedback for a fourth 20 MHzsubchannel.

In another example also illustrated in FIG. 14 , where n=16, the CSI maybe indicated by feedback start and end tone indices tables for each242-tone RU that includes:

(a) indexed tones [−500:16:−260] that provide feedback for a first 20MHz subchannel,

(b) indexed tones [−252:16:−12] that provide feedback for a second 20MHz subchannel,

(c) indexed tones [12:16:252] that provide feedback for a third 20 MHzsubchannel, and

(d) indexed tones [260:16:500] that provide feedback for a fourth 20 MHzsubchannel.

In the example illustrated in FIG. 19 for a 242-tone RU of n=4 or n=16feedback tone spacing, the feedback start/end tone indices for 80 MHzbandwidth channels includes the start/end tone indices:

[−500, −260] for a 1st indexed RU,

[−252, −12] for a 2nd indexed RU,

[12, 252] for a 3rd indexed RU, and

[260, 500] for a 4th indexed RU.

Likewise, in the example illustrated in FIG. 19 for a 242-tone RU of n=4or n=16 feedback tone spacing, the feedback start/end tone indices for160 MHz bandwidth channels includes the start/end tone indices:

[−1012, −772] for a 1st indexed RU,

[−764, −524] for a 2nd indexed RU,

[−500, −260] for a 3rd indexed RU,

[−252, −12] for a 4th indexed RU,

[12, 252] for a 5th indexed RU,

[260, 500] for a 6th indexed RU,

[524, 764] for a 7th indexed RU, and

[772, 1012] for an 8th indexed RU.

Similarly, in the example illustrated in FIG. 19 for a 242-tone RU ofn=4 or n=16 feedback tone spacing, the feedback start/end tone indicesfor 320 MHz bandwidth channels includes the start/end tone indices:

[−2036, −1796] for a 1st indexed RU,

[−1788, −1548] for a 2nd indexed RU,

[−1524, −1284] for a 3rd indexed RU,

[−1276, −1036] for a 4th indexed RU,

[−1012, −772] for a 5th indexed RU,

[−764, −524] for a 6th indexed RU,

[−500, −260] for a 7th indexed RU,

[−252, −12] for an 8th indexed RU,

[12, 252] for an 9th indexed RU.

[260, 500] for a 10th indexed RU,

[524, 764] for a 11th indexed RU,

[772, 1012] for a 12th indexed RU,

[1036, 1276] for a 13th indexed RU,

[1284, 1524] for a 14th indexed RU,

[1548, 1788] for a 15th indexed RU, and

[1796, 2036] for a 16th indexed RU.

Within the entire 80 MHz bandwidth channel or each 80 MHz segment of a160 MHz or 320 MHz bandwidth channel, if certain RU242 is not within therange of feedback request, only the feedback tones of the remainingRU242 in that 80 MHz that are within the range of feedback request aresent. Otherwise, if the entire 80 MHz bandwidth channel or each 80 MHzsegment of a 160 MHz or 320 MHz bandwidth channel is within the range offeedback request, the feedback tones of the RU996 corresponding to that80 MHz are sent.

In an example illustrated in FIG. 20 for a 996-tone RU of n=4 feedbacktone spacing, the feedback tone indices set for 80 MHz bandwidthchannels is:

[−500:4:−4, 4:4:500] for a 1st indexed RU.

In another example illustrated in FIG. 20 for a 996-tone RU of n=4feedback tone spacing, the feedback tone indices set for an entire 80MHz segment within a 160 MHz bandwidth channels is:

[−1012:4:−516, −508:4:−12] for a 1st indexed RU, and[12:4:508, 516:4:1012] for a 2nd indexed RU.

Likewise, in another example illustrated in FIG. 20 for a 996-tone RU ofn=4 feedback tone spacing, the feedback tone indices set for an entire80 MHz segment within a 320 MHz bandwidth channels is:

[−2036:4:−1540, −1532:4:−1036] for a 1st indexed RU,[−1012:4:−516, −508:4:−12] for a 2nd indexed RU,[12:4:508, 516:4:1012] for a 3rd indexed RU, and[1036:4:1532, 1540:4:2036] for a 4th indexed RU.

In an example illustrated in FIG. 21 for a 996-tone RU of n=16 feedbacktone spacing, the feedback tone indices set for 80 MHz bandwidthchannels is:

[−500:16:−260, −252:16:−12, −4, 4, 12:16:252, 260:16:500] for a 1stindexed RU.

In another example illustrated in FIG. 21 for a 996-tone RU of n=16feedback tone spacing, the feedback tone indices set for an entire 80MHz segment within a 160 MHz bandwidth channels is:

[−1012:16:−772, 764:16:−524, −516, −508, −500:16:−260, −252:16:−12] fora 1st indexed RU, and

[12:16:252, 260:16:500, 508, 516, 524:16:764, 772:16:1012] for a 2ndindexed RU.

Likewise, in another example illustrated in FIG. 21 for a 996-tone RU ofn=16 feedback tone spacing, the feedback tone indices set for an entire80 MHz segment within a 320 MHz bandwidth channels is:

[−2036:16:−1796, −1788:16:−1548, −1540, −1532, −1524:16:−1284,−1276:16:1036] for a 1st indexed RU,

[−1012:16:−772, −764:16:−524, −516, −508, −500:16:−260, −252:16:−12] fora 2nd indexed RU,

[1036:16:1276, 1284:16:1524, 1532, 1540, 1548:16:1788, 1796:16:2036] fora 4th indexed RU.

FIG. 22 is an example method 2200 for wireless communication thatprovides partial bandwidth feedback in response to receiving a puncturednull data packet.

At step 2202 a wireless communication device may receive, from a firstwireless device, a null data packet (NDP) over a channel having abandwidth that is an integer multiple of 80 MHz, the NDP including along training field (LTF) that is modulated onto a plurality of tones ofthe channel excluding tones within a punctured subchannel of a pluralityof subchannels of the channel, the modulation being based on a size anda location of the punctured subchannel and a symbol duration associatedwith transmission of the LTF sequence.

At step 2204, the wireless device may obtain and/or generate channelstate information (CSI) for the channel in response to receiving the NDPwith a feedback request for at least a portion of the channel bandwidth,the feedback request covering at least part of an 80 MHz bandwidthchannel or at least part of an 80 MHz bandwidth portion of a 160 MHzbandwidth channel or a 320 MHz bandwidth channel, the CSI including onefeedback tone for every n grouped tones of the plurality of tones of thechannel, where n=4 or 16, and the CSI is modulated in an indexed rangeof feedback tones within a 242-tone resource unit (RU) or a 996-toneresource unit (RU).

At step 2206, the wireless device may also receive, from the firstwireless device, a null data packet announcement (NDPA) over thechannel, the NDPA including a partial bandwidth information subfieldthat includes an 8-bit subfield for identifying a 242-tone resource unit(RU) start index and an end index, the partial bandwidth informationsubfield identifying an indexed range of feedback tones for the channelstate information (CSI).

At step 2208, the wireless device may transmit the CSI to the firstwireless device.

The LTF sequence may be modulated onto the plurality of tones based onan orthogonal frequency division multiple access (OFDMA) data tone planfor an 80 MHz bandwidth channel or an OFDMA data tone plan for each 80MHz segment of a channel having a bandwidth that is an integer multipleof 80 MHz.

FIG. 16 is a block diagram illustrating an example of a wireless deviceadapted to facilitate communications of punctured null data packets andpartial bandwidth feedback using a channel greater than 80 MHzbandwidth. The wireless device 1600 may be, for example, an access pointor a user station, and may be implemented with a processing system 1614that includes one or more processors 1604. Examples of processors 1604include microprocessors, microcontrollers, digital signal processors(DSPs), field programmable gate arrays (FPGAs), programmable logicdevices (PLDs), state machines, gated logic, discrete hardware circuits,and other suitable hardware configured to perform the variousfunctionality described throughout this disclosure. In various examples,the AP 1600 may be configured to perform any one or more of thefunctions described herein. That is, the processor 1604, as utilized inthe AP 1600, may be used to implement any one or more of the processes,procedures, and tables further illustrated in the flow diagram of FIGS.6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17, 18, 19, 20 and 21 .

In this example, the processing system 1614 may be implemented with abus architecture, represented generally by the bus 1602. The bus 1602may include any number of interconnecting buses and bridges depending onthe specific application of the processing system 1614 and the overalldesign constraints. The bus 1602 communicatively couples togethervarious circuits including one or more processors (represented generallyby the processor 1604), a memory 1605, and computer-readable media(represented generally by the computer-readable medium 1606). The bus1602 may also link various other circuits such as timing sources,peripherals, voltage regulators, and power management circuits, whichare well known in the art, and therefore, will not be described anyfurther. A bus interface 1608 provides an interface between the bus 1602and a wireless transceiver 1610 (comprising a transmitter and areceiver). The wireless transceiver 1610 provides a communicationinterface or means for communicating with various other apparatus over atransmission medium. For instance, the wireless transceiver 1610 maytransmit and receive to and from one or more wireless device using oneor more antennas 1616 and in accordance with an IEEE 802.11 protocol,such as IEEE 802.11be. In one implantation, the wireless transceiver1614 may operate according to a multiple input multiple output (MIMO)mode.

The processor 1604 is responsible for managing the bus 1602 and generalprocessing, including the execution of software stored on thecomputer-readable medium 1606. The software, when executed by theprocessor 1604, causes the processing system 1614 to perform the variousfunctions described below for any particular apparatus. Thecomputer-readable medium 1606 and the memory 1605 may also be used forstoring data that is manipulated by the processor 1604 when executingsoftware.

In one or more examples, the processor 1604 may include an OFDMAmodulation circuit 1640, an OFDMA demodulation circuit 1642, and a LongTraining Field for Punctured Null Data Packet (NDP) Generator circuit1644. In one example, the Long Training Field Generator circuit 1644 mayserve to obtain an EHT-LTF sequence for a 320 MHz bandwidth channel. TheOFDMA modulation circuit 1640 may serve to modulate the EHT-LTF sequenceand a data field into an OFDM signal for transmission. The OFDMAdemodulation circuit 1642 may serve to demodulate a received OFDMsignal.

One or more processors 1604 in the processing system may executesoftware. Software shall be construed broadly to mean instructions,instruction sets, code, code segments, program code, programs,subprograms, software modules, applications, software applications,software packages, routines, subroutines, objects, executables, threadsof execution, procedures, functions, etc., whether referred to assoftware, firmware, middleware, microcode, hardware descriptionlanguage, or otherwise. The software may reside on a computer-readablemedium 1606. The computer-readable medium 1606 may be a non-transitorycomputer-readable medium. A non-transitory computer-readable mediumincludes, by way of example, a magnetic storage device (such as, harddisk, floppy disk, magnetic strip), an optical disk (such as, a compactdisc (CD) or a digital versatile disc (DVD)), a smart card, a flashmemory device (such as, a card, a stick, or a key drive), a randomaccess memory (RAM), a read only memory (ROM), a programmable ROM(PROM), an erasable PROM (EPROM), an electrically erasable PROM(EEPROM), a register, a removable disk, and any other suitable mediumfor storing software or instructions that may be accessed and read by acomputer. The computer-readable medium 1606 may reside in the processingsystem 1614, external to the processing system 1614, or distributedacross multiple entities including the processing system 1614. Thecomputer-readable medium 1606 may be embodied in a computer programproduct. By way of example, a computer program product may include acomputer-readable medium in packaging materials. Those skilled in theart will recognize how best to implement the described functionalitypresented throughout this disclosure depending on the particularapplication and the overall design constraints imposed on the overallsystem.

In one or more examples, the computer-readable storage medium 1606 mayinclude OFDMA modulation instructions 1650, OFDMA demodulationinstructions 1652, or Long Training Fields for Punctured NDPinstructions 1654. Of course, in the above examples, the circuitryincluded in the processor 1604 is merely provided as an example, andother means for carrying out the described functions may be includedwithin various aspects of the present disclosure, including but notlimited to the instructions stored in the computer-readable storagemedium 1606, or any other suitable apparatus or means described in anyone of the processes or algorithms described herein.

In one mode of operation, it is contemplated that the wireless device1600 generates and transmits the punctured NDP with an LTF sequence andreceives channel feedback information. In another mode of operation, thewireless device 1600 may receive the punctured NDP with an LTF sequenceand then estimates and transmits channel state information based on thereceived LTF.

Aspect 1: A method for wireless communication by a wirelesscommunication device, comprising: obtaining a long training field (LTF)sequence for a null data packet (NDP) for transmission over a channelhaving a bandwidth that is an integer multiple of 80 MHz; modulating theLTF sequence onto a plurality of tones of the channel excluding toneswithin a punctured subchannel of a plurality of subchannels of thechannel, the modulation being based on a size and a location of thepunctured subchannel and a symbol duration associated with transmittingthe LTF sequence; and transmitting the NDP including the LTF sequence toa second wireless communication device via the channel.

Aspect 2: The method of aspect 1, further comprising: generating a nulldata packet announcement (NDPA) for transmission over the channel, theNDPA including a partial bandwidth information subfield that includes an8-bit subfield for identifying a 242-tone resource unit (RU) start indexand an end index, the partial bandwidth information subfield identifyingan indexed range of feedback tones for channel state information (CSI);and transmitting the NDPA to the second wireless communication devicevia the channel.

Aspect 3: The method of any one of aspects 1 or 2, wherein themodulation of the LTF sequence onto the plurality of tones is based onan orthogonal frequency division multiple access (OFDMA) data tone planfor an 80 MHz bandwidth channel or an OFDMA data tone plan for each 80MHz segment of a channel having a bandwidth that is an integer multipleof 80 MHz.

Aspect 4: The method of any one of aspects 1, 2, or 3, wherein thesymbol duration associated with the LTF sequence is one of: 12.8 μs plusa guard interval, 6.4 μs plus the guard interval, or 3.2 μs plus theguard interval, and wherein the guard interval is one of 0.8 μs, 1.6 us,or 3.2 μs.

Aspect 5: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 12.8 μs plus theguard interval, and wherein the LTF sequence is modulated onto each tonewithin a plurality of tone ranges of the OFDMA data tone plan, and thechannel includes an 80 MHz bandwidth portion that includes the puncturedsubchannel; the punctured subchannel has a 20 MHz bandwidth within the80 MHz bandwidth portion; the 80 MHz bandwidth portion comprises 1001tones; and the plurality of tone ranges include: tones [−253:−12,12:253, 259:500] based on the punctured subchannel being a first 20 MHzsubchannel; tones [−500:−259, 12:253, 259:500] based on the puncturedsubchannel being a second 20 MHz subchannel adjacent the first 20 MHzsubchannel; tones [−500:−259, −253:−12, 259:500] based on the puncturedsubchannel being a third 20 MHz subchannel adjacent the second 20 MHzsubchannel; or tones [−500:−259, −253:−12, 12:253] based on thepunctured subchannel being a fourth 20 MHz subchannel adjacent the third20 MHz subchannel.

Aspect 6: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 12.8 μs plus theguard interval, and wherein the LTF sequence is modulated onto each tonewithin a plurality of tone ranges of the OFDMA data tone plan, thechannel includes an 80 MHz bandwidth portion that includes the puncturedsubchannel; the punctured subchannel has a 40 MHz bandwidth within the80 MHz bandwidth portion; the 80 MHz bandwidth portion comprises 1001tones; and the plurality of tone ranges include: tones [12:253, 259:500]based on the punctured subchannel being a first 40 MHz subchannel; ortones [−500:−259, −253:−12] based on the punctured subchannel being asecond 40 MHz subchannel adjacent the first 40 MHz subchannel.

Aspect 7: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 6.4 μs plus theguard interval, and the LTF sequence is modulated onto every other tonewithin a plurality of tones ranges of the OFDMA data tone plan, and thechannel includes an 80 MHz bandwidth portion that includes the puncturedsubchannel; the punctured subchannel has a 20 MHz bandwidth within the80 MHz bandwidth portion; the 80 MHz bandwidth portion comprises 1001tones; and the plurality of tone ranges include: tones [−252:2:−12,12:2:252, 260:2:500] based on the punctured subchannel being a first 20MHz subchannel; tones [−500:2:−260, 12:2:252, 260:2:500] based on thepunctured subchannel being a second 20 MHz subchannel adjacent the first20 MHz subchannel; tones [−500:2:−260, −252:2:−12, 260:2:500] based onthe punctured subchannel being a third 20 MHz subchannel adjacent thesecond 20 MHz subchannel; or tones [−500:2:−260, −252:2:−12, 12:2:252]based on the punctured subchannel being a fourth 20 MHz subchanneladjacent the third 20 MHz subchannel.

Aspect 8: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 6.4 μs plus theguard interval, and the LTF sequence is modulated onto every other tonewithin a plurality of tones ranges of the OFDMA data tone plan, and thechannel includes an 80 MHz bandwidth portion that includes the puncturedsubchannel; the punctured subchannel has a 40 MHz bandwidth within the80 MHz bandwidth portion; the 80 MHz bandwidth portion comprises 1001tones; and the plurality of tone ranges include: tones [12:2:252,260:2:500] based on the punctured subchannel being a first 40 MHzsubchannel; or tones [−500:2:−260, −252:2:−12] based on the puncturedsubchannel being a second 40 MHz subchannel adjacent the first 40 MHzsubchannel.

Aspect 9: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 3.2 μs plus a guardinterval, and the LTF sequence is modulated onto every fourth tonewithin a plurality of tones ranges of the OFDMA data tone plan is, andthe channel includes an 80 MHz bandwidth portion that includes thepunctured subchannel; the punctured subchannel has a 20 MHz bandwidthwithin the 80 MHz bandwidth portion; the 80 MHz bandwidth portioncomprises 1001 tones; and the plurality of tone ranges include: tones[−252:4:−12, 12:4:252, 260:4:500] based on the punctured subchannelbeing a first 20 MHz subchannel; tones [−500:4:−260, 12:4:252,260:4:500] based on the punctured subchannel being a second 20 MHzsubchannel adjacent the first 20 MHz subchannel; tones [−500:4:−260,−252:4:−12, 260:4:500] based on the punctured subchannel being a third20 MHz subchannel adjacent the second 20 MHz subchannel; or tones[−500:4:−260, −252:4:−12, 12:4:252] based on the punctured subchannelbeing a fourth 20 MHz subchannel adjacent the third 20 MHz subchannel.

Aspect 10: The method of any one of aspects 1, 2, 3, or 4, wherein thesymbol duration associated with the LTF sequence is 3.2 μs plus a guardinterval, and the LTF sequence is modulated onto every fourth tonewithin a plurality of tones ranges of the OFDMA data tone plan is, andthe channel includes an 80 MHz bandwidth portion that includes thepunctured subchannel; the punctured subchannel has a 40 MHz bandwidthwithin the 80 MHz bandwidth portion; the 80 MHz bandwidth portioncomprises 1001 tones; and the plurality of tone ranges include: tones[12:4:252, 260:4:500] based on the punctured subchannel being a first 40MHz subchannel; or tones [−500:4:−260, −252:4:−12] based on thepunctured subchannel being a second 40 MHz subchannel adjacent the first20 MHz subchannel.

Aspect 11: The method of any one of aspects 1, 2, or 3, furthercomprising: receiving channel state information (CSI) for the channel inresponse to transmitting the NDP with a partial feedback request, thepartial feedback request covering less than an 80 MHz bandwidth channelor less than an 80 MHz bandwidth portion of a 160 MHz bandwidth channelor a 320 MHz bandwidth channel, the CSI including one feedback tone forevery n grouped tones of the plurality of tones of the channel where n=4or 16, and wherein the CSI is received in an indexed range of feedbacktones within a 242-tone resource unit (RU).

Aspect 12: The method of aspect 11, wherein for the 242-tone RU of n=4or n=16 feedback tone spacing, the feedback start/end tone indices forthe 80 MHz bandwidth channel include the start/end tone indices: (a)indexed tones [−500, −260] that provide feedback for a first 20 MHzsubchannel of the 80 MHz bandwidth channel, (b) indexed tones [−252, 12]that provide feedback for a second 20 MHz subchannel of the 80 MHzbandwidth channel, (c) indexed tones [12, 252] that provide feedback fora third 20 MHz subchannel of the 80 MHz bandwidth channel, and (d)indexed tones [260, 500] that provide feedback for a fourth 20 MHzsubchannel of the 80 MHz bandwidth channel.

Aspect 13: The method of aspect 11, wherein for the 242-tone RU of n=4or n=16 feedback tone spacing, the feedback start/end tone indices forthe 80 MHz bandwidth portion of the 160 MHz bandwidth channel includethe start/end tone indices: [−1012, −772] for a 1st indexed RU, [−764,−524] for a 2nd indexed RU, [−500, −260] for a 3rd indexed RU, [−252,−12] for a 4th indexed RU, [12, 252] for a 5th indexed RU, [260, 500]for a 6th indexed RU, [524, 764] for a 7th indexed RU, and [772, 1012]for an 8th indexed RU.

Aspect 14: The method of aspect 11, wherein for the 242-tone RU of n=4or n=16 feedback tone spacing, the feedback start/end tone indices forthe 80 MHz bandwidth portion of the 320 MHz bandwidth channel includesthe start/end tone indices: [−2036, −1796] for a 1st indexed RU, [−1788,−1548] for a 2nd indexed RU, [−1524, −1284] for a 3rd indexed RU,[−1276, −1036] for a 4th indexed RU, [−1012, −772] for a 5th indexed RU,[−764, −524] for a 6th indexed RU, [−500, −260] for a 7th indexed RU,[−252, −12] for an 8th indexed RU, [12, 252] for an 9th indexed RU,[260, 500] for a 10th indexed RU, [524, 764] for a 11th indexed RU,[772, 1012] for a 12th indexed RU, [1036, 1279] for a 13th indexed RU,[1284, 1524] for a 14th indexed RU, [1548, 1788] for a 15th indexed RU,and [1796, 2036] for a 16th indexed RU.

Aspect 15: The method of aspect 1, further comprising: receiving channelstate information (CSI) for the channel in response to the transmittingthe NDP with a feedback request for the entire channel bandwidth, thefeedback request covering an entire 80 MHz bandwidth channel or anentire 80 MHz bandwidth portion of a 160 MHz bandwidth channel or a 320MHz bandwidth channel, the CSI including one feedback tone for every ngrouped tones of the plurality of tones of the channel, where n=4 or 16,and the CSI is received in an indexed range of feedback tones within a996-tone resource unit (RU).

Aspect 16: The method of anyone of aspects 1 or 15, wherein a feedbacktone set for the entire 80 MHz bandwidth channel within the 996-tone RUfor n=4 feedback tone spacing is defined as [−500:4:−4, 4:4:500],spanning a region of 1001 tones [−500 to +500], every 4 tones, and witha DC tone region between [−4:4].

Aspect 17: The method of anyone of aspects 1 or 15, wherein a feedbacktone set for the entire 160 MHz bandwidth channel within the 996-tone RUfor n=4 feedback tone spacing is indicated by feedback start and endtone indices tables for each 996-tone RU that include: (a) indexed tones[−1012:4:−516, −508:4:−12] that provide feedback for a first 80 MHzsubchannel of the 160 MHz bandwidth channel, and (b) indexed tones[12:4:508, 516:4:1012] that provide feedback for a second 80 MHzsubchannel of the 160 MHz bandwidth channel.

Aspect 18: The method anyone of aspects 1 or 15, wherein a feedback toneset for the entire 320 MHz bandwidth channel within the 996-tone RU forn=4 feedback tone spacing is indicated by feedback start and end toneindices tables for each 996-tone RU that include: (a) indexed tones[−2036:4:−1540, −1532:4:−1036] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, (b) indexed tones[−1012:4:−516, −508:4:−12] that provide feedback for a second 80 MHzsubchannel of the 320 MHz bandwidth channel, (c) indexed tones[12:4:508, 516:4:1012] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, and (d) indexedtones[1036:4:1532, 1540:4:2036] that provide feedback for a second 80MHz subchannel of the 320 MHz bandwidth channel.

Aspect 19: The method of anyone of aspects 1 or 15, wherein a feedbacktone set for the entire 80 MHz bandwidth channel within the 996-tone RUfor n=16 feedback tone spacing is indicated by feedback start and endtone indices tables for each 996-tone RU that include indexed tones[−500:16:−260, −252:16:−12, −4, 4, 12:16:252, 260:16:500], spanning aregion of 1001 tones [−500:500], every 16 tones, and with a DC toneregion between [−4:4].

Aspect 20: The method of anyone of aspects 1 or 15, wherein a feedbacktone set for the entire 160 MHz bandwidth channel within the 996-tone RUfor n=16 feedback tone spacing is indicated by feedback start and endtone indices tables for each 996-tone RU that include: (a) indexed tones[−1012:16:−772, 764:16:−524, −516, −508, −500:16:−260, −252:16:−12] thatprovide feedback for a first 80 MHz subchannel of the 160 MHz bandwidthchannel, and (b) indexed tones [12:16:252, 260:16:500, 508, 516,524:16:764, 772:16:1012] that provide feedback for a second 80 MHzsubchannel of the 160 MHz bandwidth channel.

Aspect 21: The method of anyone of aspects 1 or 15, wherein a feedbacktone set for the entire 320 MHz bandwidth channel within the 996-tone RUfor n=16 feedback tone spacing is indicated by feedback start and endtone indices tables for each 996-tone RU that include: (a) indexed tones[−2036:16:−1796, −1788:16:−1548, −1540, −1532, −1524:16:−1284,−1276:16:1036] that provide feedback for a first 80 MHz subchannel ofthe 320 MHz bandwidth channel, (b) indexed tones [−1012:16:−772,−764:16:−524, −516, −508, −500:16:−260, −252:16:−12] that providefeedback for a second 80 MHz subchannel of the 320 MHz bandwidthchannel, (c) indexed tones [12:16:252, 260:Ng=16:500, 508, 516,524:16:764, 772:16:1012] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, and (d) indexed tones[1036:16:1276, 1284:16:1524, 1532, 1540, 1548:16:1788, 1796:16:2036]that provide feedback for a second 80 MHz subchannel of the 320 MHzbandwidth channel.

Aspect 22: A wireless communication device, comprising: at least oneprocessor; and at least one memory communicatively coupled with the atleast one processor and storing processor-readable code that, whenexecuted by the at least one processor, is configured to: obtain a longtraining field (LTF) sequence for a null data packet (NDP) fortransmission over a channel having a bandwidth that is an integermultiple of 80 MHz; modulate the LTF sequence onto a plurality of tonesof the channel excluding tones within a punctured subchannel of aplurality of subchannels of the channel, the modulation being based on asize and a location of the punctured subchannel and a symbol durationassociated with transmitting the LTF sequence; and transmit the NDPincluding the LTF sequence to a second wireless communication device viathe channel.

Aspect 23: The wireless communication device of aspect 22, wherein theat least one processor further configured to: generate a null datapacket announcement (NDPA) for transmission over the channel, the NDPAincluding a partial bandwidth information subfield that includes an8-bit subfield for identifying a 242-tone resource unit (RU) start indexand an end index, the partial bandwidth information subfield identifyingan indexed range of feedback tones for channel state information (CSI);and transmit the NDPA to the second wireless communication device viathe channel.

Aspect 24: The wireless communication device of anyone of aspects 22 or23, wherein the modulation of the LTF sequence onto the plurality oftones is based on an orthogonal frequency division multiple access(OFDMA) data tone plan for an 80 MHz bandwidth channel or an OFDMA datatone plan for each 80 MHz segment of a channel having a bandwidth thatis an integer multiple of 80 MHz.

Aspect 25: A method for wireless communication by a wirelesscommunication device, comprising: receiving, from a first wirelessdevice, a null data packet (NDP) over a channel having a bandwidth thatis an integer multiple of 80 MHz, the NDP including a long trainingfield (LTF) that is modulated onto a plurality of tones of the channelexcluding tones within a punctured subchannel of a plurality ofsubchannels of the channel, the modulation being based on a size and alocation of the punctured subchannel and a symbol duration associatedwith transmission of the LTF sequence; generating channel stateinformation (CSI) for the channel in response to receiving the NDP witha feedback request for at least a portion of the channel bandwidth, thefeedback request covering at least part of an 80 MHz bandwidth channelor at least part of an 80 MHz bandwidth portion of a 160 MHz bandwidthchannel or a 320 MHz bandwidth channel, the CSI including one feedbacktone for every n grouped tones of the plurality of tones of the channel,where n=4 or 16, and the CSI is modulated in an indexed range offeedback tones within a 242-tone resource unit (RU) or a 996-toneresource unit (RU); and transmitting the CSI to the first wirelessdevice.

Aspect 26: The method of aspect 25, further comprising: receiving, fromthe first wireless device, a null data packet announcement (NDPA) overthe channel, the NDPA including a partial bandwidth information subfieldthat includes an 8-bit subfield for identifying a 242-tone resource unit(RU) start index and an end index, the partial bandwidth informationsubfield identifying an indexed range of feedback tones for the channelstate information (CSI).

Aspect 27: The method of anyone of aspects 25 or 26, wherein the LTFsequence is modulated onto the plurality of tones based on an orthogonalfrequency division multiple access (OFDMA) data tone plan for an 80 MHzbandwidth channel or an OFDMA data tone plan for each 80 MHz segment ofa channel having a bandwidth that is an integer multiple of 80 MHz.

Aspect 28: The method of anyone of aspects 25, 26, or 27, wherein thefeedback request is a partial feedback request for less than the 80 MHzbandwidth channel or less than the 80 MHz bandwidth portion of the 160MHz bandwidth channel or the 320 MHz bandwidth channel, the CSIincluding one feedback tone for every n grouped tones of the pluralityof tones of the channel where n=4 or 16, and wherein the CSI ismodulated in an indexed range of feedback tones within the 242-toneresource unit (RU).

Aspect 29: The method of anyone of aspects 25, 26, 27, or 28, whereinfor the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth channel include thestart/end tone indices: (a) indexed tones [−500, −260] that providefeedback for a first 20 MHz subchannel of the 80 MHz bandwidth channel,(b) indexed tones [−252, 12] that provide feedback for a second 20 MHzsubchannel of the 80 MHz bandwidth channel, (c) indexed tones [12, 252]that provide feedback for a third 20 MHz subchannel of the 80 MHzbandwidth channel, and (d) indexed tones [260, 500] that providefeedback for a fourth 20 MHz subchannel of the 80 MHz bandwidth channel.

Aspect 30: The method of anyone of aspects 25, 26, 27, or 28, whereinfor the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth portion of the 160 MHzbandwidth channel include the start/end tone indices: [−1012, −772] fora 1st indexed RU, [−764, −524] for a 2nd indexed RU, [−500, −260] for a3rd indexed RU, [−252, −12] for a 4th indexed RU, [12,252] for a 5thindexed RU, [260, 500] for a 6th indexed RU, [524, 764] for a 7thindexed RU, and [772, 1012] for an 8^(th) indexed RU.

Aspect 31: The method of anyone of aspects 25, 26, 27, or 28, whereinfor the 242-tone RU of n=4 or n=16 feedback tone spacing, the feedbackstart/end tone indices for the 80 MHz bandwidth portion of the 320 MHzbandwidth channel includes the start/end tone indices: [−2036, −1796]for a 1st indexed RU, [−1788, −1548] for a 2nd indexed RU, [−1524,−1284] for a 3rd indexed RU, [−1276, −1036] for a 4th indexed RU,[−1012, −772] for a 5th indexed RU, [−764, −524] for a 6th indexed RU,[−500, −260] for a 7th indexed RU, [−252, −12] for an 8th indexed RU,[12, 252] for an 9th indexed RU, [260, 500] for a 10th indexed RU, [524,764] for a 11th indexed RU, [772, 1012] for a 12th indexed RU, [1036,1276] for a 13th indexed RU, [1284, 1524] for a 14th indexed RU, [1548,1788] for a 15th indexed RU, and [1796, 2036] for a 16th indexed RU.

Aspect 32: The method of anyone of aspects 25, 26, or 27, wherein thefeedback request is an entire feedback request covering the entire 80MHz bandwidth channel or the entire 80 MHz bandwidth portion of the 160MHz bandwidth channel or the 320 MHz bandwidth channel, the CSIincluding one feedback tone for every n grouped tones of the pluralityof tones of the channel where n=4 or 16, and wherein the CSI ismodulated in an indexed range of feedback tones within the 996-toneresource unit (RU).

Aspect 33: The method of anyone of aspects 25, 26, 27, or 32, wherein afeedback tone set for the entire 80 MHz bandwidth channel within the996-tone RU for n=4 feedback tone spacing is defined as [−500:4:−4,4:4:500], spanning a region of 1001 tones [−500 to +500], every 4 tones,and with a DC tone region between [−4:4].

Aspect 34: The method of anyone of aspects 25, 26, 27, or 32, wherein afeedback tone set for the entire 160 MHz bandwidth channel within the996-tone RU for n=4 feedback tone spacing is indicated by feedback startand end tone indices tables for each 996-tone RU that include: (a)indexed tones [−1012:4:−516, −508:4:−12] that provide feedback for afirst 80 MHz subchannel of the 160 MHz bandwidth channel, and (b)indexed tones [12:4:508, 516:4:1012] that provide feedback for a second80 MHz subchannel of the 160 MHz bandwidth channel.

Aspect 35: The method of anyone of aspects 25, 26, 27, or 32, wherein afeedback tone set for the entire 320 MHz bandwidth channel within the996-tone RU for n=4 feedback tone spacing is indicated by feedback startand end tone indices tables for each 996-tone RU that include: (a)indexed tones [−2036:4:−1540, −1532:4:−1036] that provide feedback for afirst 80 MHz subchannel of the 320 MHz bandwidth channel, (b) indexedtones [−1012:4:−516, −508:4:−12] that provide feedback for a second 80MHz subchannel of the 320 MHz bandwidth channel, (c) indexed tones[12:4:508, 516:4:1012] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, and (d) indexedtones[1036:4:1532, 1540:4:2036] that provide feedback for a second 80MHz subchannel of the 320 MHz bandwidth channel.

Aspect 36: The method of anyone of aspects 25, 26, 27, or 32, wherein afeedback tone set for the entire 80 MHz bandwidth channel within the996-tone RU for n=16 feedback tone spacing is indicated by feedbackstart and end tone indices tables for each 996-tone RU that includeindexed tones [−500:16:−260, −252:16:−12, −4, 4, 12:16:252, 260:16:500],spanning a region of 1001 tones [−500:500], every 16 tones, and with aDC tone region between [−4:4].

Aspect 37: The method of anyone of aspects 25, 26, 27, or 32, wherein afeedback tone set for the entire 160 MHz bandwidth channel within the996-tone RU for n=16 feedback tone spacing is indicated by feedbackstart and end tone indices tables for each 996-tone RU that include: (a)indexed tones [−1012:16:−772, 764:16:−524, −516, −508, −500:16:−260,−252:16:−12] that provide feedback for a first 80 MHz subchannel of the160 MHz bandwidth channel, and (b) indexed tones [12:16:252, 260:16:500,508, 516, 524:16:764, 772:16:1012] that provide feedback for a second 80MHz subchannel of the 160 MHz bandwidth channel.

Aspect 38: The method of anyone of aspects 25, 26, or 27, wherein afeedback tone set for the entire 320 MHz bandwidth channel within the996-tone RU for n=16 feedback tone spacing is indicated by feedbackstart and end tone indices tables for each 996-tone RU that include: (a)indexed tones [−2036:16:−1796, −1788:16:−1548, −1540, −1532,−1524:16:−1284, −1276:16:1036] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, (b) indexed tones[−1012:16:−772, −764:16:−524, −516, −508, −500:16:−260, −252:16:−12]that provide feedback for a second 80 MHz subchannel of the 320 MHzbandwidth channel, (c) indexed tones [12:16:252, 260:Ng=16:500, 508,516, 524:16:764, 772:16:1012] that provide feedback for a first 80 MHzsubchannel of the 320 MHz bandwidth channel, and (d) indexed tones[1036:16:1276, 1284:16:1524, 1532, 1540, 1548:16:1788, 1796:16:2036]that provide feedback for a second 80 MHz subchannel of the 320 MHzbandwidth channel.

Aspect 39: A wireless communication device, comprising: at least oneprocessor; and at least one memory communicatively coupled with the atleast one processor and storing processor-readable code that, whenexecuted by the at least one processor, is configured to: receive, froma first wireless device, a null data packet (NDP) over a channel havinga bandwidth that is an integer multiple of 80 MHz, the NDP including along training field (LTF) that is modulated onto a plurality of tones ofthe channel excluding tones within a punctured subchannel of a pluralityof subchannels of the channel, the modulation being based on a size anda location of the punctured subchannel and a symbol duration associatedwith transmission of the LTF sequence; generate channel stateinformation (CSI) for the channel in response to receiving the NDP witha feedback request for at least a portion of the channel bandwidth, thefeedback request covering at least part of an 80 MHz bandwidth channelor at least part of an 80 MHz bandwidth portion of a 160 MHz bandwidthchannel or a 320 MHz bandwidth channel, the CSI including one feedbacktone for every n grouped tones of the plurality of tones of the channel,where n=4 or 16, and the CSI is modulated in an indexed range offeedback tones within a 242-tone resource unit (RU) or a 996-toneresource unit (RU); and transmit the CSI to the first wireless device.

Aspect 40: The wireless communication device of aspect 39, wherein theat least one processor is further configured to: receiving, from thefirst wireless device, a null data packet announcement (NDPA) over thechannel, the NDPA including a partial bandwidth information subfieldthat includes an 8-bit subfield for identifying a 242-tone resource unit(RU) start index and an end index, the partial bandwidth informationsubfield identifying an indexed range of feedback tones for the channelstate information (CSI).

Aspect 41: The wireless communication device of anyone of aspects 39 or40, wherein the LTF sequence is modulated onto the plurality of tonesbased on an orthogonal frequency division multiple access (OFDMA) datatone plan for an 80 MHz bandwidth channel or an OFDMA data tone plan foreach 80 MHz segment of a channel having a bandwidth that is an integermultiple of 80 MHz.

As used herein, “or” is used intended to be interpreted in the inclusivesense, unless otherwise explicitly indicated. For example, “a or b” mayinclude a only, b only, or a combination of a and b. As used herein, aphrase referring to “at least one of” or “one or more of” a list ofitems refers to any combination of those items, including singlemembers. For example, “at least one of: a, b, or c” is intended to coverthe examples of: a only, b only, c only, a combination of a and b, acombination of a and c, a combination of b and c, and a combination of aand b and c.

The various illustrative components, logic, logical blocks, modules,circuits, operations and algorithm processes described in connectionwith the implementations disclosed herein may be implemented aselectronic hardware, firmware, software, or combinations of hardware,firmware or software, including the structures disclosed in thisspecification and the structural equivalents thereof. Theinterchangeability of hardware, firmware and software has been describedgenerally, in terms of functionality, and illustrated in the variousillustrative components, blocks, modules, circuits and processesdescribed above. Whether such functionality is implemented in hardware,firmware or software depends upon the particular application and designconstraints imposed on the overall system.

Various modifications to the implementations described in thisdisclosure may be readily apparent to persons having ordinary skill inthe art, and the generic principles defined herein may be applied toother implementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein, but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Additionally, various features that are described in this specificationin the context of separate implementations also can be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation also can beimplemented in multiple implementations separately or in any suitablesubcombination. As such, although features may be described above asacting in particular combinations, and even initially claimed as such,one or more features from a claimed combination can in some cases beexcised from the combination, and the claimed combination may bedirected to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one or moreexample processes in the form of a flowchart or flow diagram. However,other operations that are not depicted can be incorporated in theexample processes that are schematically illustrated. For example, oneor more additional operations can be performed before, after,simultaneously, or between any of the illustrated operations. In somecircumstances, multitasking and parallel processing may be advantageous.Moreover, the separation of various system components in theimplementations described above should not be understood as requiringsuch separation in all implementations, and it should be understood thatthe described program components and systems can generally be integratedtogether in a single software product or packaged into multiple softwareproducts.

What is claimed is:
 1. A method for wireless communication by a wirelesscommunication device, comprising: modulating a long training field (LTF)sequence for a null data packet (NDP) onto a plurality of tones of awireless channel that includes one or more 80 MHz bandwidth segments,the modulation excluding tones within a punctured subchannel of aplurality of subchannels of an 80 MHz bandwidth segment of the wirelesschannel, the modulation being based on a size and a location of thepunctured subchannel within the 80 MHz bandwidth segment, an 80 MHzorthogonal frequency division multiple access (OFDMA) tone plan, and asymbol duration associated with transmitting the LTF sequence, wherein:(a) the symbol duration associated with the LTF sequence is 12.8 μs plusa guard interval, the LTF sequence is modulated onto each tone within aplurality of tone ranges of the OFDMA data tone plan, the puncturedsubchannel has a 20 MHz bandwidth within the 80 MHz bandwidth segment,the 80 MHz bandwidth segment comprises 1001 tones, and the plurality oftone ranges include: tones [−253:−12, 12:253, 259:500] based on thepunctured subchannel being a first 20 MHz subchannel; tones [−500:−259,12:253, 259:500] based on the punctured subchannel being a second 20 MHzsubchannel adjacent the first 20 MHz subchannel; tones [−500:−259,−253:−12, 259:500] based on the punctured subchannel being a third 20MHz subchannel adjacent the second 20 MHz subchannel; or tones[−500:−259, −253:−12, 12:253] based on the punctured subchannel being afourth 20 MHz subchannel adjacent the third 20 MHz subchannel, (b) thesymbol duration associated with the LTF sequence is 12.8 μs plus theguard interval, the LTF sequence is modulated onto each tone within aplurality of tone ranges of the OFDMA data tone plan, the puncturedsubchannel has a 40 MHz bandwidth within the 80 MHz bandwidth segment,the 80 MHz bandwidth segment comprises 1001 tones, and the plurality oftone ranges include: tones [12:253, 259:500] based on the puncturedsubchannel being a first 40 MHz subchannel; or tones [−500:−259,−253:−12] based on the punctured subchannel being a second 40 MHzsubchannel adjacent the first 40 MHz subchannel, (c) the symbol durationassociated with the LTF sequence is 6.4 μs plus the guard interval, theLTF sequence is modulated onto every other tone within a plurality oftones ranges of the OFDMA data tone plan, the punctured subchannel has a20 MHz bandwidth within the 80 MHz bandwidth segment, the 80 MHzbandwidth segment comprises 1001 tones, and the plurality of tone rangesinclude: tones [−252:2:−12, 12:2:252, 260:2:500] based on the puncturedsubchannel being a first 20 MHz subchannel; tones [−500:2:−260,12:2:252, 260:2:500] based on the punctured subchannel being a second 20MHz subchannel adjacent the first 20 MHz subchannel; tones [−500:2:−260,−252:2:−12, 260:2:500] based on the punctured subchannel being a third20 MHz subchannel adjacent the second 20 MHz subchannel; or tones[−500:2:−260, −252:2:−12, 12:2:252] based on the punctured subchannelbeing a fourth 20 MHz subchannel adjacent the third 20 MHz subchannel,or (d) the symbol duration associated with the LTF sequence is 6.4 μsplus the guard interval, the LTF sequence is modulated onto every othertone within a plurality of tones ranges of the OFDMA data tone plan, thepunctured subchannel has a 40 MHz bandwidth within the 80 MHz bandwidthsegment, the 80 MHz bandwidth segment comprises 1001 tones, and theplurality of tone ranges include: tones [12:2:252, 260:2:500] based onthe punctured subchannel being a first 40 MHz subchannel; or tones[−500:2:−260, −252:2:−12] based on the punctured subchannel being asecond 40 MHz subchannel adjacent the first 40 MHz subchannel; andtransmitting the NDP including the modulated LTF sequence to a secondwireless communication device via the wireless channel.